Akutagawa, a prominent figure in Yokohama's Mafia, served as a high-ranking and invaluable pawn under his boss's command. On a particular day, he was tasked with dealing with an organization threatening the Port Mafia's bank. Accompanied by lower-ranking members, the encounter resulted in a fierce battle, leaving Akutagawa as the sole survivor, his body battered and bruised, clothes soaked in a grim mixture of his own and others' blood.

In a precarious situation, the distant Mafia headquarters and the unfeasibility of seeking help at a hospital forced Akutagawa to consider an unconventional refuge—the Armed Detective Agency, a rival to the Mafia. Despite the enmity, it stood as the only plausible option. Struggling up the stairs, Akutagawa navigated the modest and unassuming apartment building, a stark contrast to his own opulent residence funded by his lucrative position.

Clutching his side, blood oozing from his wounds, he cast a desperate gaze around until his eyes fixated on a nameplate reading 'Nakajima'—the surname of his rival. Without hesitation, he rapped on the door, breaths labored, attempting to maintain composure amidst the pain.

"Jinko?" he rasped, the name hanging in the air for a few moments as he panted once again.