Chapter Text
Chuuya is laughing again.
That’s the first thing Dazai notices when he steps into the hallway outside the training room, the bright, careless sound of Chuuya’s voice, warm and easy in a way it almost never is around him. It takes him a moment to locate the source, and when he does, he stops walking.
Tachihara is standing too close.
Too close to Chuuya.
Too close to what’s his.
Chuuya doesn’t seem to mind. He’s leaning against the wall, arms crossed, smirk tugging at his mouth as he humors whatever foolish thing Tachihara’s blushing through.
The distance between them is thin, just enough for Tachihara to pretend he isn’t eyeing the way Chuuya’s hair falls over his collar, the slight curve of his smile, the way he shifts his weight.
Dazai watches them from the shadows of the corridor, unreadable. He doesn’t move, doesn’t interrupt, doesn’t even make his presence known.
He just watches.
Because Dazai Osamu—demon prodigy, Port Mafia executive, and future Armed Detective Agency menace—was never known to be possessive of anything. Not power, not status, not territory, not weapons, not missions.
Those things were tools, conveniences, temporary.
Chuuya, however—Chuuya was an anomaly.
A fixed point in Dazai’s world.
A gravitational force all on his own.
Something Dazai had no intention of sharing with anyone.
Especially not with a boy like Tachihara, whose blush is deepening the longer he stands there.
Down the hall, a pair of mafiosi walk by, glance toward the trio, and immediately look away. Their silence is telling. Their quickened steps are even more so.
Everyone in the Port Mafia knows the rule.
No one touches Nakahara Chuuya.
Not because of Corruption, or his gravity manipulation ability, or Chuuya’s short temper and devastating kicks.
But because of Dazai.
Because the last idiot who tried hadn’t been seen in days.
Because executives learned quickly to avoid unnecessary contact.
Because rumors spread fast when someone mysteriously vanished after getting a little too “friendly.”
And Tachihara—young, stupid Tachihara—either hasn’t heard the rule or believes he’s an exception.
Chuuya laughs again at something he says.
Dazai’s fingers twitch.
It’s not rage.
Not jealousy, not exactly.
It’s something sharper. Older. Ugly in a way Dazai recognizes intimately.
Possession.
A quiet, coiling thing that whispers: Mine.
Tachihara finally reaches out, a casual touch to Chuuya’s arm, fingers brushing the sleeve like a flirt half-testing his luck.
Dazai’s smile presses thin.
That’s enough.
He steps out of the shadows, hands in his pockets, expression light, lazy, harmless.
And Chuuya straightens, sensing him like he always does, like his body instinctively knows when Dazai is near.
“Oi, Dazai,” Chuuya says, irritated but familiar. “How long’ve you been standing there?”
Dazai tilts his head, smile widening just a little too much.
“Long enough.”
And the unspoken rule hums through the air like a threat sharpened to a blade.
Nobody touches Nakahara Chuuya.
Not if they want to live.