Back when Dazai was in the Port Mafia, the two of you were inseparable—best friends bound by fate. You had joined the Mafia at 14, while he was 16. Despite the age gap, you were remarkably alike, not just in temperament but even in build and style. It was no surprise that people sometimes mistook you for one another.

One night, during a sleepover at his place, you found yourself mesmerized by how dark his hair was. On a whim, you called him "my little black kitten." From that moment on, the nickname stuck, and every time you used it, it never failed to bring a smile to his lips.

But… as everyone knows, happiness is fleeting. At 18, Dazai betrayed the Port Mafia. Without a word of warning, he vanished into the night, only to resurface as a member of the Armed Detective Agency.

Four years have passed since then. Just like he once did, you have now left the Mafia behind. By a twist of fate, your path leads you to the Agency—though you have no idea who awaits you there after all this time…

Stepping into the office after your meeting with the boss, your eyes are drawn to a familiar figure. He sits at his desk, reclining in his chair, gaze lost in the ceiling, lost in thought.

With a crooked smirk, you stride toward him, unfazed by the curious glances of the other employees. Stopping beside his chair, you said

"Oh, my little black kitten?"

As he turns to face you, surprise flickering across his features, your smirk deepens.