Work Text:
Gen steps off the jet bridge in just a shirt and light jacket, pulling his carry-on behind him, and tells himself the chill on his skin is just leftover cabin air. Behind him, Senku is already muttering, “Fourteen‑hour offset, air moisture at seventy‑four percent.”, counting time stamps under his breath. Gen’s lips curve at the familiar sound. It keeps him steady.
Customs goes faster than expected and their bags show up even quicker. When the automatic doors slide open they find Byakuya Ishigami holding a perfectly ordinary sign that reads “SENKU & GEN!! WELCOME TO HOUSTON”. No glitter, just clean black marker. Low-effort on the surface, full-effort underneath.
Byakuya’s eyes light up and he drops the sign on a bench so his arms are free. “Senkuuu! My favorite son in the universe! Welcome!” Byakuya calls out, his voice booming with excitement and his grin so wide it could light up the whole terminal. His arms are already open for a hug before he's even halfway across the floor. Senku goes stiff but only for a heartbeat before patting his dad’s back in return.
“Dad. We are in public.” Senku mutters, ears burning.
“It's okay, airports are public‑hug zones.” Byakuya answers, then turns with equal warmth to Gen. “Gen! Finally face‑to‑face after all those calls.”
Gen steps in, half raising a hand for a shake, half leaning forward for a hug. “Thank you for picking us up, Mr Ishig-” he catches himself, the words stumbling. “Byakuya.”
The name feels new on his tongue and he blushes slightly, but Byakuya’s smile only widens. “That’s it. Much better.” He pulls Gen into a warm squeeze, quick but full of welcome. “If you call me ‘mister’ again, I’ll assign you homework instead.”
Gen lets out a small, breathy laugh that helps shake the nerves loose. "Got it. Good to meet you face to face."
“Screens never do it justice.” Byakuya says, releasing him yet keeping a steadying hand on his shoulder. “Thank you for keeping my favorite scientist alive and at least moderately fed.”
“He knows how to operate a microwave.” Gen replies, cheeks coloring. “I just make sure he uses it before he passes out.”
“Team effort then.” Byakuya grins.
Senku clears his throat. “We should get moving before dad starts crying.” The words sound gruff, but the faint curl at the corner of his mouth betrays him, he’s quietly happy to see his dad and his boyfriend getting along so easily.
Byakuya scoops up the sign. “Come on, I parked close. Long flight, shorter walk. Hope the flight behaved.”
“No engine harmonics above tolerance.” Senku says while his eyes dart over the suitcases, already figuring out which are theirs.
Gen falls in beside him, shoulders loosening when Senku’s knuckles brush his. They spot their bags quickly and head straight to the garage, their steps in quiet sync.
They reach a chalk‑gray SUV in the parking deck and pile in. Byakuya adjusts the mirror while Senku buckles up behind him and Gen claims the passenger seat, palms flat on his knees.
“So, cramped seats and airline meals aside.” Byakuya asks “How was the flight?”
“Cabin pressure held steady.” Senku answers. “Gen finished two documentaries and half a novel.”
Gen shrugs, smiling. “Kept myself awake by sampling all the mini crackers.”
Byakuya chuckles as they merge onto the freeway. “Perfect. We’ll stock the pantry so you can continue your studies under controlled kitchen conditions.” He taps the steering wheel. “So, here’s the rough plan. Tomorrow we keep it low‑key. Monday starts with orientation at Johnson Space Center. After that it’s internship hours for this one” he nods toward Senku “and tourist freedom for you, Gen. I’ve got two weeks off, so if you want a tour guide, or just someone to hang out with, I’m around. Or, if you'd prefer, you can join me for some rocket tests.”
Gen blinks, caught off guard, needing a moment to process the words. “Wait, is that a real invitation?” His eyebrows lift.
“Absolutely. I have visitor badges ready.”
Senku glances forward. “Dad just wants to show off the centrifuge.”
“Guilty.” Byakuya admits. “We’re not doing anything heroic tonight. Just home for a quick wash-up, a big slice of warm bread from the oven, and sleep so deep the alarm clock will need backup.”
Gen hums in agreement, relaxing as neon signage and billboards slide past the windows.
★☆★
Byakuya lives on the fourth floor of a red‑brick building near Buffalo Bayou Park. Inside the apartment features clean lines, white walls, and floor‑to‑ceiling windows that let in soft natural light and offer a wide view of the park below. The front door opens into one big room where the kitchen and living area share the same space, with a short open hall off to two bedrooms and the shared bath. The main space smells of cooling rosemary bread.
Byakuya gestures. “Make yourselves at home. Shower, stretch, whatever you need to do.”
Senku opens his mouth, probably to outline a five‑step plan, but Byakuya points a gentle finger. “After twelve hours in the air you are not reading a single spec sheet until dinner, Senku.”
Senku’s reply is a soft grumble that holds no real protest.
Gen stands half a pace behind, eyes drifting over framed photos. Rockets, beaches, a younger Senku in a too‑big lab coat. He folds his hands so the slight tremor hides in his palm.
Byakuya waves them down the short hall. "Guest room’s at the end. Big bed, fresh sheets and extra blankets in the closet. Bathroom is right across."
The room is small but bright, all clean white walls and a deep‑blue comforter spread over a queen mattress. A pair of fluffy towels waits on the dresser.
Byakuya pats the doorframe. "Drop your bags, breathe for a minute. I’ll get dinner started so you can settle. Call if you need anything." He backs away, giving them a quick thumbs‑up before disappearing toward the kitchen.
For the first time since landing, the apartment goes quiet. Just the distant clatter of pans and a faint radio playing while Byakuya cooks. Senku sets their luggage against the wall and glances at Gen. Despite his precise calculation of their fourteen-hour offset, even Senku feels a faint heaviness lingering behind his eyes, the subtle reminder of travel fatigue catching up. The nervous edge around Gen’s shoulders eases a fraction now that they’re alone.
Senku turns. “You okay?”
“Good.” he says, voice light but paper‑thin. “Shaking off plane seat memory.” Gen shifts his weight from one foot to the other, half‑laughing, yet his knuckles stay white on the handle. Tired shadows rest under his eyes. Senku notices how high Gen’s shoulders sit and how carefully he breathes. It’s the same look he wore after finals week. Wrung-out, running on nerves instead of rest. He’s been here before. Gen pretending calm when he’s clearly running low on energy.
“You sure you’re fine?” Senku asks again.
Gen straightens his collar. “Fine. Really.”
Senku’s gaze lingers. He does not look convinced. He steps closer until their knees almost touch. “We can talk now if something feels off. New city, new walls... I know that can rattle.”
Gen exhales. “It’s not bad. Just new. Your dad is... very welcoming.”
Senku waits.
Gen’s shoulders ease. “I don’t want to trip over expectations.”
“There are none.” Senku says. “He made bread, not exams.”
A puff of laughter escapes Gen, the edge in his shoulders softens for real this time. “Bread I can handle. And this is more bed than I’ve used in years.”
“Plenty of space. No elbows to the ribs.” Senku says.
“Space is overrated.” Gen whispers.
Senku’s ears tint pink but he lets the words rest. “Bathroom’s down the hall.” He points. “You first.”
Gen nods and collects his toiletries. In the hall he pauses for a moment, taking a steady breath before stepping into the shared bath with quiet ease. He shuts the door and turns the lock. His breath leaves in a slow, silent sigh.
★☆★
Byakuya sets down lasagna smelling of garlic and basil. Two baskets of rosemary bread wait beside it, crust shining with olive oil. Sparkling water beads on two mismatched glasses, while Gen got a cold glass of cola.
“Safe flights and new beginnings.” Byakuya says. They clink glasses.
Conversation begins with flight‑delay jokes, drifts to Houston warmth, then lands on Monday’s schedule. Gen follows easily until father and son slide into NASA territory.
“Gateway is still running heavy.” Byakuya says with a small sigh. “Every layer of heat shield adds kilos we did not plan for.”
Senku leans forward, eyes bright. “Could you swap in lighter tiles? Even a few percent matters.”
“We tried foam panels last month.” Byakuya replies. “They save mass but they didn’t hold up under stress.”
Senku nods, but Gen doesn’t quite follow and raises an eyebrow. Byakuya, noticing, adds, “Basically, the foam couldn’t handle simulated ocean air.” slowly.
“What about cutting the cryo tank size? Less fuel means less boil‑off to manage.”
“That idea is on the table.” Byakuya says. “They have a meeting on Tuesday. Bring it up, they will like a fresh voice.”
Gen twirls his pasta and nods now and then. His fork slows. He slides a glance to Senku whose eyes shine, completely at ease. Gen’s grip betrays him with a faint tremor, he lowers the fork.
Byakuya notices the way Gen’s fork pauses and how his gaze starts to drift. “Sorry, we go too deep. Changing lane. Gen, what do you think of Houston so far?”
Relief flickers, then presents as a bright smile. “Big sky. Bigger highways. Interesting aromas. This remains the best scent though.” He gestures at the lasagna.
“Thank you. Old family recipe.” Byakuya grins.
Senku nudges Gen’s knee under the table, a silent you ok? Gen nudges back.
After plates disappear, dessert arrives. Dark chocolate loaf with honey drizzle. Gen eats in small bites. Senku’s commentary pauses unless Byakuya asks something directly, his attention stays on Gen, subtle but constant.
The dishes are done, the AC humming softly and the apartment settles. Byakuya heads to his room. Senku clicks off the kitchen light then turns in the hall. He walks down the short corridor to the guest room door where Gen stands by the bed, looking a little unsteady. Without a word Senku reaches out and gently slips his fingers through Gen’s, a small, reassuring gesture that warms the quiet space.
“Hey. You look like you’re measuring every step. What are you watching out for?”
Gen shrugs. “First trip with the boyfriend, living in his dad’s flat... hard to know what counts as good manners.”
“Gen. I like you. Dad likes you. Those are the only metrics, okay?” Senku says.
“Seems like metrics feel different inside my head.” Gen answers.
Senku steps closer. “You helped with dishes. That wins him over more than anything.”
A soft laugh. The tension loosens a little.
★☆★
They change into soft pajamas in the guest room. Senku pulls his shirt over his head, quiet, as Gen brushes back his hair, tugging sweatpants over his bare feet.
Senku clicks off the overhead light. For a moment only the soft hum of the air conditioner fills the silence. Gen slips into bed first, intentionally choosing the side against the wall. He leaves an unusual gap between them, noticeably wide compared to their usual tangled closeness at home.
Senku settles on the outer edge, a faint crease appearing between his eyebrows at Gen’s careful distance. It feels odd and out of character, their beds at home are always cramped and comfortably crowded.
Silence settles, stretching out softly beneath the glow-in-the-dark stars scattered on the ceiling.
Eventually, Senku gently reaches out, fingertips finding Gen’s palm in the dark. Gen stills, then carefully curls his fingers around Senku’s hand, holding tight but not moving closer.
They lie hand-in-hand for several quiet minutes before Senku breaks the silence, voice low and careful. “Mind if you come a bit closer?”
Gen turns to meet his gaze, hesitating a moment before offering a small, unsure smile. “I thought you’d enjoy the extra space. Our beds at home are always too cramped.”
Senku smiles softly, squeezing Gen’s hand. “Space is overrated.”
Gen chuckles quietly, voice muffled against Senku’s shoulder as he shifts closer. “Hey, that was my line.”
Gen’s shoulder relaxes as soon as he’s pressed into Senku’s warmth, tension melting out of his body with a soft sigh. Senku drapes an arm comfortably around his waist, using his other hand to slowly stroke through Gen’s hair, soothing and gentle.
After a moment, Senku murmurs, “Still nervous?”
Gen speaks softly into Senku’s shirt, eyes already growing heavy. “Less.” he admits. “Your father is kind. He makes it look easy. I keep waiting to drop a plate.”
Senku’s thumb brushes lightly along Gen’s temple. “Plates are replaceable. You’re not.”
Heat blooms softly across Gen’s cheeks, visible even in the dimness. “High praise, Ishigami.”
“Observation.” Senku corrects warmly, thumb gently brushing Gen’s hairline, tucking a loose strand behind his ear.
Senku continues these careful movements, Gen’s breaths gradually evening into deep, peaceful sleep.
Senku closes his own eyes, warmth settling comfortably in his chest. When he’s certain Gen’s asleep, he whispers quietly into the dark “Good night, mentalist.”
Only Gen’s steady breathing answers, warm and safe under the faint glow of stars on the ceiling.
★☆★
The Houston morning arrived softly, filtering through the blinds in warm, muted lines. Gen was the first to open his eyes, blinking slowly until the unfamiliar ceiling sharpened into focus. For a moment, he was disoriented until he felt Senku's arm loosely draped around his waist, fingers splayed lightly over his ribs.
He shifted carefully, turning just enough to look at Senku's face. In sleep, Senku looked younger, less intense. His brow was relaxed, the ever-present crease between his eyebrows smoothed away. Gen watched the gentle rise and fall of Senku’s chest, content to remain quiet and close.
Eventually, Senku's eyes flickered open, meeting Gen's almost immediately. He blinked once, twice, and then the faintest smile tugged at his lips. "Morning."
"Good morning.“ Gen whispered, hesitant to disturb the quiet.
Senku stretched, the warmth of his hand briefly tightening against Gen’s side. "Sleep okay?"
Gen chuckled softly. "Considering I didn't elbow you in the ribs this time, I'd say yes."
Senku smirked. "There's still time."
"I'm feeling generous.“ Gen replied dryly, shifting to sit up. "I'll save it for another day."
Senku rose alongside him, ruffling his hair lazily. "Big day tomorrow. Nervous?"
"Me?" Gen scoffed lightly, tilting his chin up playfully. "Never."
Senku raised an eyebrow. "Really? Because you talked in your sleep."
Gen froze momentarily, his cheeks warming. "What did I say?"
"Something about astronauts and bread.“ Senku teased, clearly enjoying Gen’s embarrassment. "Very profound."
Gen groaned, flopping dramatically back onto the pillows. "How charming. My subconscious is sabotaging me again."
Senku laughed quietly, leaning over to brush a gentle kiss against Gen’s forehead. "Relax. You’re going to be fine."
They spent the rest of Sunday easing into the new space. Byakuya gave them a short walking tour of the park nearby, pointing out the small lake and the quiet reading garden tucked behind a row of oaks. Gen helped slice vegetables for dinner while Senku tinkered with Byakuya’s coffee machine, claiming it was operating below optimal pressure. The day passed slowly and softly, filled with sunshine, familiar voices, and no pressure to perform.
It wasn’t until late that night that Senku finally picked up his tablet and started reviewing research notes, but even then, he only lasted twenty minutes before Gen gently took it from his hands and swapped it for a pillow.
★☆★
Byakuya greeted them in the kitchen, already awake and moving cheerfully around the stove. "Morning! Hope you’re hungry. I made pancakes. NASA-shaped pancakes."
Senku’s eyes narrowed suspiciously. "Please tell me they’re not rocket-shaped."
Byakuya grinned mischievously. "Only some of them."
Gen slid into a chair at the table, clearly amused. "Wow, I was not prepared for this level of pancake art early in the morning."
"See, Senku?" Byakuya laughed, flipping a pancake effortlessly. "At least someone appreciates culinary creativity around here."
"It's not creativity, Dad.“ Senku said dryly. "It's culinary dad jokes."
Byakuya set plates down in front of them, full of golden pancakes and fresh fruit. "Culinary dad jokes with maple syrup are far better than your average breakfast, I assure you."
Gen smiled into his coffee. The atmosphere felt welcoming, but his nerves prickled beneath the easy conversation. Today was Senku’s NASA orientation and despite his earlier confidence, Gen felt a little overwhelmed. And he was just being a visitor.
Senku glanced sideways at him, picking up on the subtle tightness in Gen’s posture. "You okay?" he asked softly, nudging Gen’s knee under the table.
"Of course.“ Gen replied, managing a convincing smile. "Just mentally preparing to meet more geniuses."
"You deal with me daily.“ Senku joked. "You’ll be fine."
Byakuya overheard, sliding into a seat opposite them with a warm chuckle. "If you survive Senku, you can handle anything NASA throws at you. Trust me."
Gen relaxed slightly, grateful for Byakuya’s reassuring presence. "I’ll hold you both to that."
★☆★
The drive to NASA felt surprisingly short, filled with casual chatter between Senku and Byakuya, with a few comfortable pauses Gen appreciated deeply. Byakuya pulled smoothly into a reserved parking spot near the visitor's entrance and turned off the engine.
"Welcome to Johnson Space Center.“ Byakuya announced warmly, glancing at Gen in the rearview mirror. "Ready?"
"As I'll ever be.“ Gen said, stepping out of the car into the bright Houston sunlight.
The campus sprawled impressively before them, modern buildings mixed with older structures, all linked by neat pathways lined with greenery. People moved about purposefully, ID badges gleaming around their necks.
"Feels a bit surreal.“ Gen murmured, fingers tracing the fabric of his shirt as if to ground himself against the rising tension.
Senku came up beside him, bumping Gen’s shoulder lightly with his own. "They’re all just people. Smart people, yes. But still just people."
Gen raised an eyebrow. "Easy for the genius to say."
Senku rolled his eyes but smiled slightly. "Trust me, they're all nerds at heart."
Byakuya led them inside, greeting several passing colleagues warmly. "Okay Senku, your mentor should be here any minute now. Remember, Dr. Xeno might seem a bit intimidating at first, but he's genuinely a good person."
Senku scoffed, though Gen noticed the way he tugged briefly at his sleeve, a small nervous gesture that was rare for Senku.
Gen leaned closer, voice low. "It's okay to admit you're a little star-struck."
"I'm not star-struck.“ Senku muttered defensively, then paused as footsteps approached.
“Ishigami.”
A tall, silver-haired man appeared with a composed, authoritative presence. Beside him was another man, tall and sharp-eyed, with a well-built frame that hinted at a disciplined lifestyle. His visitor badge said Stanley, printed in clear black letters against a white background.
"Dr. Xeno.“ Byakuya said brightly "This is my son, Senku, your new intern. And this is his partner, Gen, visiting with us."
Xeno’s eyes scanned Senku briefly, a subtle approval flickering in his expression. "Senku Ishigami. I've heard a lot about you."
"Likewise.“ Senku replied evenly, shaking hands firmly. Gen noticed how straight Senku stood, as if pride pulled his spine straighter.
Stanley gave a brief nod of greeting to both Senku and Gen, reserved but polite. "Welcome aboard, Senku."
Byakuya added with a smile, "Stanley's not with NASA, he works with the military. But he's here visiting a lot. Also happens to be Dr. Xeno's husband."
Gen blinked in surprise, but Stanley just gave a subtle, knowing smile.
Byakuya turned kindly toward Gen. "Come on, Gen. I’ll show you around. We’ll leave these science types to their business."
"Good luck.“ Gen said lightly, but he caught Senku’s gaze and softened his voice. "Have fun."
Senku nodded, gratitude and excitement shimmering quietly in his eyes. "Thanks. See you later."
As Byakuya guided Gen away, Gen glanced back once more. Senku stood confidently, listening intently to Xeno’s introduction. In that moment, Gen felt a swell of pride, briefly overshadowing his own uncertainty. If nothing else, he could be sure of Senku and for now, that was enough.
★☆★
Byakuya led Gen through the wide halls of the Johnson Space Center with an ease that came from familiarity. Gen’s eyes wandered over the plaques, pictures, and occasional displays of space items lining the corridors. Each item reinforced the extraordinary reality of where he was.
"It's impressive, isn't it?" Byakuya asked, glancing at Gen with a warm smile. "Even after years, this place still amazes me."
Gen nodded, swallowing around the slight lump in his throat. "Yes. It's a lot to take in."
"You'll get used to it.“ Byakuya reassured him gently. "And trust me, you belong here as much as anyone. Senku brought you because he wants you here. That’s all that matters."
Gen’s cheeks heated slightly at that. "I know. But I suppose it's different for me. I'm not exactly NASA material."
Byakuya chuckled, shaking his head. "Gen, everyone here has their own strength. Yours might not be rockets and equations, but your talent with people... it's just as important. Probably more, considering Senku needs someone to help him translate his thoughts to human language sometimes."
Gen laughed softly, relieved at the gentle humor. "That's true. I’m basically his PR department."
Byakuya's smile widened. "Exactly. See, we need you."
They walked slowly through the rest of the visitor area, Byakuya casually greeting colleagues and introducing Gen as my son's partner, which felt surprisingly good. Gen liked how natural Byakuya made it sound, as if their relationship was entirely normal and accepted without question.
Eventually they reached the exit, stepping back into the Houston sunlight. Byakuya glanced at his watch. "Senku said his orientation runs about eight hours today, so we've got plenty of time. Wanna go shopping? I promised I'd help you update your wardrobe and I keep my promises."
Gen hesitated slightly, embarrassment creeping into his expression. "You really don't have to. I appreciate it, but-"
Byakuya waved him off kindly. "Nonsense. Senku mentioned you couldn’t bring many clothes when you left your ex, so you don’t have much. You need clothes, and I’m happy to help."
Gen sighed dramatically, though his eyes sparkled. "Well, if you insist."
"I do.“ Byakuya said firmly, guiding Gen toward his car. "Call it a welcome gift. From me to you."
★☆★
The mall they visited was bright, modern, and bustling with mid-afternoon shoppers. Byakuya navigated the stores with a confident pace, leading Gen straight into a stylish clothing boutique.
Gen trailed behind him, eyes wide at the chic displays. "Byakuya, you do realize I usually shop at thrift stores, right? This looks expensive."
Byakuya just smiled reassuringly. "Gen, I work for NASA and own two apartments. Buying you clothes is not going to bankrupt me."
Gen chuckled, relaxing slightly. "Alright, but if Senku complains about this, you're taking the blame."
"Deal.“ Byakuya said cheerfully, already scanning racks and shelves. "Now, let's pick something Senku will like."
Gen raised an eyebrow, amused. "We're shopping based on Senku’s taste now?"
"We'll make sure to grab things you actually like, too. This isn’t just about impressing my son. But trust me, it'll be fun.“ Byakuya laughed, holding up a shirt featuring a quirky Mars Rover graphic with the line I came. I saw. I roved. "How about this one? Senku will definitely appreciate the humor."
Gen shook his head fondly, smiling despite himself. "He would, wouldn't he? Alright, why not."
They moved through several more racks, selecting various shirts and sweaters, each with subtle nods to space or science, just enough to amuse Senku without being overly cheesy. One featured a cartoon rocket launching with a slice of toast inside and the slogan: "Breakfast? I prefer launch." Gen laughed so hard he nearly dropped it, and insisted they add it to the pile immediately. He found himself genuinely enjoying the process, smiling easily at Byakuya’s jokes and stories about Senku’s childhood.
"Did Senku really build a rocket at age ten?" Gen asked, eyes wide in astonishment.
"Oh, yes.“ Byakuya said, fondness evident in his tone. "Nearly set off the entire floor’s smoke alarm system. I still don’t know how he avoided a building-wide evacuation. There was smoke, a very angry neighbor, and Senku just saying ‘technically it worked.’"
"Well.“ Gen said wryly, inspecting a sweatshirt covered in constellation patterns "At least he’s consistent."
Byakuya laughed warmly. "Consistent is one way to put it. Stubbornly determined might be another."
Gen smiled softly, running his fingers over the soft fabric of the sweatshirt. "I guess it's one of the things I admire about him."
"Me too.“ Byakuya said gently, placing a comforting hand on Gen’s shoulder. "And I’m glad he's found someone who appreciates that stubborn determination."
Gen's cheeks warmed slightly, but he met Byakuya's gaze openly. "Thanks. That means a lot."
Byakuya squeezed his shoulder gently before stepping back. "Anytime. Now, let's finish up here and grab something for dinner. Senku will probably be starving by the time he’s done."
★☆★
Back at the apartment Gen carried his new clothes into the guest room, feeling lighter and surprisingly comforted by the afternoon spent with Byakuya. Senku arrived not long after, entering with an energy Gen immediately recognized as excitement.
"Welcome back.“ Gen said softly, noticing the spark in Senku’s eyes. "How was the first day?"
"Good.“ Senku replied, trying to appear nonchalant but failing miserably. "Xeno’s intense, but I like him. He doesn't waste time on trivial things."
Gen chuckled, stepping closer and smoothing the front of Senku’s shirt. "Sounds perfect for you."
Senku’s gaze softened, his voice gentler. "You were okay with my dad today?"
"Yes.“ Gen reassured quickly. "Better than okay. Your dad’s amazing."
Senku relaxed visibly, his hand finding Gen’s easily. "I'm glad."
Gen tilted his head slightly, smiling warmly. "And did you miss me at all, or were you too distracted by rockets?"
"Maybe.“ Senku admitted quietly, squeezing Gen’s hand gently. "But only a little."
Gen laughed, shaking his head fondly. "Of course. Only a little."
Senku smirked, leaning forward just enough for their foreheads to touch lightly. "Come on. Dad surely wants the full mission report, and I forgot a real lunch, I just grabbed a protein bar, because my brain decided to prioritize rocket specs."
Gen smiled softly, contentment settling warmly within him. "Lead the way."
★☆★
Byakuya prepared spaghetti carbonara with ease, humming a familiar tune while he cooked. Senku leaned against the counter, arms folded, occasionally rolling his eyes but smiling softly. Gen sat at the dining table, observing them quietly and just feeling a warmth in his chest.
Byakuya placed the dish proudly on the table, eyes bright. "Alright, dinner is served! Hope it tastes as good as it smells."
Senku poked at the spaghetti skeptically. "Dad, did you measure the cheese, or did you just guess again?"
Byakuya scoffed playfully. "It's called intuition, Senku. Cooking isn't rocket science."
Senku raised an eyebrow, pretending offense. "It literally should be, though."
Gen chuckled softly, relaxing a bit at their playful banter. "It smells amazing, Byakuya. I'm sure it's perfect."
Byakuya beamed at Gen. "Thank you, Gen. At least someone appreciates my culinary genius."
They ate in comfortable silence for a moment, the sound of forks against plates soft and steady. Gen watched quietly as Senku and Byakuya began discussing NASA matters, their conversation quickly shifting into technical terms that left him utterly lost.
"So the new propulsion tests, Senku.“ Byakuya began, leaning forward eagerly. "How did Xeno describe the efficiency levels?"
"He mentioned hitting nearly eighty-seven percent, which is a pretty big deal,“ Senku replied, his eyes alight with excitement. "If they sustain that, it could revolutionize deep-space missions."
Byakuya nodded enthusiastically. "Exactly! And what about the thermal control system? Did he mention anything new?"
Senku shook his head. "Not much. Xeno said the insulation they're using now reduces heat loss by another three percent, which might sound small, but it's important."
"Three percent in space missions? That's huge.“ Byakuya agreed quickly. "Every decimal counts."
Gen smiled faintly, stirring his pasta absently, not comprehending most of the conversation but enjoying the obvious passion in their voices.
"Sorry.“ Senku murmured softly, glancing sideways at Gen. "Dad and I got carried away. Again."
Gen shook his head, smiling warmly. "Don't apologize. It's nice to see you both excited."
Byakuya looked up, eyes softening. "Gen, feel free to interrupt us whenever. We can talk about something less scientific."
"No, no.“ Gen laughed gently, waving a hand. "I actually enjoy listening, even if I don't understand half of it."
Byakuya chuckled, giving Senku a meaningful glance. "See, Senku? He's a keeper."
Senku rolled his eyes but couldn't hide his smile. "I already knew that."
Gen felt his cheeks warm slightly, ducking his head shyly.
The rest of dinner passed pleasantly. By the time they cleared the table, the sky outside had darkened, stars starting to appear faintly through the apartment window.
Senku yawned widely, stretching his arms above his head. "I'm beat. The first day took more out of me than I expected."
Byakuya clapped his hands once, gently. "You two go relax. I'll handle the dishes."
Gen moved to protest, but Byakuya shook his head firmly. "No arguments. Go unwind."
"Thanks, Dad.“ Senku said softly, tugging Gen's hand gently toward the guest room. Gen allowed himself to be led, his heart fluttering gently at the casual intimacy of Senku’s touch.
★☆★
The following days passed in a blur of busy mornings and quiet evenings. Senku’s internship at NASA consumed most of his attention, but he always found time to text Gen, sharing little updates of his experiences.
Tuesday
Wednesday
Thursday
Friday
Saturday
★☆★
On Saturday evening, in the guest room, Gen was already curled up comfortably in the bed when Senku joined him. They lay close, shoulders and hips lightly touching. Despite having enough space, they naturally gravitated toward each other, warmth radiating softly between them.
"Good week?" Gen murmured gently.
"Amazing.“ Senku replied, eyes bright even in the dim light. "Even better than I imagined."
Gen chuckled softly. "I could tell. Your texts were practically vibrating."
"Sorry.“ Senku laughed quietly, rolling slightly closer. "Guess I got carried away."
"Don't be.“ Gen whispered. "It’s nice seeing you so excited."
They settled into silence, Gen’s fingers tracing lazy patterns over the blanket. After a moment, he cautiously moved his hand, letting it drift lower until it hovered briefly just above Senku’s hipbone, fingertips barely grazing the fabric of his sleep pants. Senku stiffened slightly, his breath hitched for a second.
Gen immediately withdrew, concern flooding his voice. "Sorry, I didn't mean-"
"No.“ Senku quickly interrupted, forcing himself to relax. His heart beat faster than expected, his nerves on edge simply because it felt unfamiliar, not unwelcome. "It's not you. Just... I'm not really used to this."
Gen's voice softened even further. "You don’t have to explain. We can take it slower."
Senku exhaled slowly, meeting Gen’s gaze earnestly. "I want this, Gen. It’s just... new territory."
"And that’s completely fine.“ Gen murmured soothingly. "There’s no rush."
Senku reached over, gently taking Gen’s hand and interlacing their fingers. "Thank you for understanding."
Gen smiled tenderly, leaning closer until their foreheads touched lightly. "Of course. Just tell me if anything feels uncomfortable, okay?"
"Okay." Senku whispered.
A quiet pause hung between them, gentle and safe. Senku eventually spoke, his voice softer, threaded with excitement again. "Next week at NASA should be even better. Xeno hinted at a new project he wants me involved in."
"Sounds exciting." Gen replied, genuine warmth in his voice.
"Yeah." Senku agreed softly. "And knowing I get to come home to this every night makes it even better."
"You really mean that?" Gen asked, a little breathless, the weight of the moment surprising him. Senku had been so wrapped up in NASA and everything happening in Houston that Gen couldn’t help the swell of quiet joy at knowing he still mattered that much.
"Wouldn’t have said it otherwise." Senku replied, eyes steady and sure.
They shifted slightly closer, settling comfortably into the reassuring presence of each other. Within their little bubble, everything felt right, safe, and perfect.
Eventually, Gen’s eyelids began to droop. Senku noticed, gently brushing hair from Gen’s face. "Sleep. Your nervous system will thank you."
"Mmmmm." Gen hummed contentedly, curling in a little closer. "Goodnight, genius."
"Goodnight, mentalist." Senku replied, allowing himself to relax fully.
Wrapped in each other’s gentle presence, sleep found them easily, carrying them into peaceful dreams of the days yet to come.
★☆★
Sunday arrived with a gentle breeze drifting through the open window. Gen woke up slowly, his senses first registering the soft morning light, and then the steady pressure of fingers stroking gently through his hair. He blinked awake, turning his head slightly to find Senku sitting upright beside him, back propped against the headboard. One of Senku’s hands rested lazily in Gen’s hair, stroking it in slow, absent patterns. The motion was grounding, oddly soothing. Gen smiled sleepily as he tilted his head slightly toward the touch. Senku was scrolling through his phone like it was the most normal thing in the world.
“Morning.” Gen mumbled sleepily, stretching slightly.
Senku glanced at him, a small, soft smile appearing. "Morning. Sleep well?"
"Perfectly.“ Gen replied softly, shifting a little closer.
Senku put his phone aside. "I have an idea for today."
Gen raised an eyebrow playfully. "Should I be worried?"
Senku snorted softly. "Statistically speaking, yes." he said with a small laugh, clearly amused. "Houston fair. Want to go?"
Gen’s eyes lit up, his excitement clearly visible. "A fair? Absolutely! Wait... are you actually asking me out, genius?"
Senku shrugged, smirking. "I suppose you could call it a date. If you insist."
Gen laughed warmly. "I insist."
After breakfast, they spent the day relaxing until the afternoon arrived, when they began preparing for their date. Gen chose a casual yet stylish shirt that he had picked out with Byakuya earlier that week, a soft purple fabric patterned with white tiny rocket ships and orbit paths, the print subtle but clever. Senku looked up, then blinked rapidly.
"It's from my shopping tour with your dad. You like?" Gen asked, lifting an eyebrow.
Senku coughed, his voice catching. "I... uh. It's... yeah. It's... fine."
Gen raised both brows, clearly not buying the weak response. "Fine?"
Senku scratched the back of his neck, his face going pink. "I mean. It's just a shirt. A very... purple shirt."
Gen stepped a little closer, smirking. "Byakuya said, 'Trust me, it'll be fun.' Now I get what he meant."
Senku avoided his gaze, mumbling, "I'm blaming him for this."
"You're allowed to be flustered, you know.“ Gen said lightly. "I take it as a compliment."
Senku muttered something unintelligible under his breath, and Gen beamed. He hadn’t expected Senku to react quite that strongly and now, he was definitely wearing this shirt again.
★☆★
The fair was already lively when they arrived, full of laughter, bright colors, and the rich aroma of fried food. Senku glanced around, clearly taking mental notes of everything he saw, while Gen eagerly tugged him towards the center.
"Look! Cotton candy!" Gen exclaimed, eyes sparkling. "I haven't had it in ages."
"I see the fair has already activated your chaos mode." Senku teased, though his eyes were fond.
"Yeah. And you're here for it!" Gen shot back smoothly. He reached for his wallet, but Senku was already handing over cash to the vendor.
"I've got it." Senku said without looking at him. "I'm paying for everything today. Don't worry about it." He'd invited Gen out, it was only logical, and a little satisfying, to treat him.
Gen hesitated for a second, then gave a half-smile. "Well, I won't argue with a man on a mission." He accepted the cotton candy, taking a bite with exaggerated delight. "I like being spoiled. It's charming."
Senku watched with mild amusement.
"You're ridiculous.“ He murmured, unable to hide the fondness in his voice.
"Says the man funding my sugar spiral.“ Gen replied, grinning. "You're complicit now, you know. No turning back."
Senku chuckled, shaking his head slightly. "Yeah, yeah. I’m weak."
As the evening approached, the crowd thickened. Senku instinctively reached out, clasping Gen's hand firmly. Gen glanced down, smiling gently as he squeezed Senku’s hand reassuringly.
"Just checking. You're good? Lots of people around." Gen asked quietly, leaning close.
"Yes.“ Senku replied firmly, pulling him a little closer. "Just don’t lose me."
"Never.“ Gen promised softly, heart fluttering gently.
They wandered the fair leisurely, laughing at the games and booths until Gen stopped suddenly in front of a claw machine filled with plush toys. His gaze locked onto a particular plush, a soft gray cat wearing a pirate hat.
"Oh my god, look! This is like the cutest thing I’ve ever seen in my life. It has a pirate hat, Senku. A hat!“ Gen said, nudging Senku’s shoulder.
Senku eyed the machine skeptically. "Those are rigged, you know."
“Oh?” Gen raised an eyebrow. “Enlighten me.”
Senku crossed his arms, eyes narrowing slightly as he focused on the machine. “These machines are specifically calibrated to only grip strongly enough every so often. It's called a payout rate. Most of the time, the claw is programmed to apply minimal grip strength, making it almost impossible to win.”
“Hmmm. Rigged indeed.” Gen hummed, intrigued. “So, what’s the trick then? Some people actually managed to win these things now and then, after all. It couldn’t be completely hopeless."
Senku smirked lightly. “Observation and timing. You watch a few people play to see how often the claw actually grips properly fully grips. Then, you position it carefully, going for a plush that’s positioned favorably, preferably on top or not trapped underneath others. Basically, you strike when the machine is due to pay out. It's all about patience and careful observation.”
Gen chuckled softly. “Of course, you’ve analyzed the entire process.”
“Hey, would you expect any less?” Senku replied with a faint, confident grin. “Now let me prove it. For science."
After two warm-up rounds to learn the claw’s pattern, Senku managed to successfully grasp the pirate cat plush on his third try. Gen cheered delightedly, accepting the plush and immediately hugging it close.
"Senku! That... was impressive! Like... wow!" Gen said, wide-eyed. He blinked at the pirate cat in his arms like he couldn't quite believe it. "You actually did it!"
"Told you?" Senku teased gently, "Though, admittedly, there was at least a ten percent luck factor." The corner of his mouth curved with more pride than usual.
"Yeah, but honestly. You are amazing." Gen hugged the plush tightly to his chest, stunned and a little giddy. "I mean, who even wins at these things? That was unreal."
Senku glanced away, the tips of his ears going pink as he fought back a smile he couldn't quite hide.
★☆★
As the sky darkened, the scattered lights of the ferris wheel caught their attention. Senku eyed it skeptically but Gen’s hopeful expression was impossible to resist.
"Can we go? Please?" Gen asked gently, eyes pleading softly.
Senku exhaled quietly, dragging out a sigh like he was being terribly inconvenienced, though the glint in his eyes gave him away. "This is the most cliché thing to do on a date."
"Exactly.“ Gen said with a grin.
Senku shook his head, but a faint smile tugged at the corner of his mouth. "If I must."
They stepped into a carriage and settled side by side as it gently rose into the night sky. The city stretched below them, lights flickering into life as darkness settled over the sky. Senku pointed toward the skyline, his voice thoughtful. "You can see the whole campus from here... and there, that’s my dad’s building. Kinda wild." Gen stared out, mesmerized, when suddenly fireworks exploded across the horizon, painting vibrant colors against the black canvas.
"Did you know about this?" Gen asked, turning quickly to Senku, his eyes wide with wonder.
Senku just smiled and shrugged slightly, watching the sky. "Maybe."
"Senku.“ Gen breathed softly, tears forming at the corners of his eyes. "You’ve officially ruined all future dates for me."
Senku turned slightly, taking in Gen’s emotional expression. Without thinking, he gently cupped Gen’s cheek, wiping a tear away with his thumb.
"You're crying.“ Senku murmured softly, eyes full of gentle concern.
"Happy tears.“ Gen reassured quietly, smiling.
Senku's gaze softened even more. He leaned in slowly, hesitantly brushing his lips against Gen’s in a soft, tender kiss. Their hearts pounded fast, warmth spreading between them as the kiss deepened naturally. Senku’s hands drifted slowly to Gen’s waist, pulling him closer.
Gen parted his lips slightly, deepening the kiss carefully, pouring everything he felt into it. Senku tensed for a split second, startled by the heat behind it, but then relaxed as the warmth spread from his chest outward. Their mouths moved together with growing confidence, breath mixing in the narrow space between them. When Gen’s tongue brushed gently against Senku’s lower lip, Senku froze.
Just for a moment.
He'd never done this before. Not like this. Not with tongue, not with this much closeness. His brain just... stopped.
His heart hammered sharply in his chest, thoughts scattering briefly at the intensity of it all. It wasn't unpleasant, just overwhelming in its newness.
But then he blinked, heat blooming across his cheeks. He opened to the kiss slowly, shyly, letting Gen lead. Gen’s tongue moved with gentle confidence, exploring the unfamiliar territory with a careful, teasing touch. There was a brief clumsiness to it, a hint of inexperience that made it all the more tender. His pulse was racing and his thoughts scattered. All he could feel was Gen’s warmth, the pressure of his mouth, the taste of spun sugar and something uniquely Gen. It was overwhelming and intimate and entirely new.
Above them, fireworks painted the sky in bursts of red and gold, streaks of violet and blue reflected in Gen’s lashes. And Senku felt another kind of explosion in his chest. One that wasn’t chemical or theoretical, but real and alive and happening right here, inside him.
When they finally pulled apart, both were breathless. Gen’s cheeks were flushed, lips parted in awe. He leaned forward until their foreheads rested together, holding Senku’s gaze.
"Wow.“ Gen whispered, voice shaking slightly.
Senku blinked, still catching up, heart thundering. "Definitely wow.“ he murmured, the faintest tremor in his voice.
★☆★
Later, cozied up comfortably in bed, Gen hugged his pirate cat plush affectionately, still visibly glowing from the evening. He turned his head slightly to look at Senku, who was lying beside him, a soft look in his eyes.
"That was the best date I've ever had.“ Gen said quietly. "No joke. The fair, the fireworks, that ridiculous claw machine. I would sit through a hundred science dinners with you and your dad if it meant getting another night like this."
Senku raised an eyebrow, lips lifting. "That could be arranged."
Gen chuckled and squeezed the plush tighter. "This little guy is going to remind me of you every time I see him. When you're at NASA, I’ll just cuddle this pirate cat and pretend it’s my genius boyfriend."
Senku gave the plush a dramatic look.
"Jealous?" Gen asked, catching his expression and grinning.
"Maybe a little.“ Senku muttered, face warming.
"Don't worry. The cat is backup, not replacement." Gen grinned, placing a kiss on Senku’s cheek.
"I’m watching that thing anyway." Senku smirked, pulling him closer.
They settled closer, the hush of the night folding around them. After a moment of silence, Senku shifted slightly.
"Hey, uhm. About the kiss on the ferris wheel.“ he said quietly, his voice low and careful. "That was... new. But I liked it. Even if I had no idea what I was doing."
Gen smiled softly. "You did great. Honestly, I was kind of pouring my heart into it. Sorry if I overwhelmed you."
Senku shook his head gently. "No. It felt... good. Intense. But good. I think I just needed a second to catch up."
Gen’s hand found Senku’s, giving it a small squeeze. "Next time we do something that intense, I’ll warn you. Maybe."
Senku gave him a dry look, but the corners of his mouth were lifted.
Wrapped in each other’s warmth, Gen rested his head on Senku’s shoulder, the plush cat tucked between them. Outside, the city lights glimmered like the echoes of fireworks, and inside, everything felt calm, safe, and perfectly new.