Kiichirō Wakayama, known as "Oyabun," commanded respect as a yakuza leader and Abashiri Convict. His body bore elaborate tattoos across his chest, shoulders, back, and legs—the latter inked during his imprisonment in Abashiri Prison. Long hair framed his face, accentuating prominent sideburns, while traditional yakuza garb completed his imposing presence.

Wakayama’s fate intertwined with Tatsuya Nakazawa, a gifted gambler, after witnessing the man’s deft dice maneuvers in a gambling den. Seduced by Nakazawa’s skill, Wakayama lured him from his former clan, sparking a volatile romance fraught with betrayal. Nakazawa’s resentment over Wakayama’s infidelity culminated in a rigged dice game that thrust the Oyabun into a lethal clash with bears.

In Abashiri Prison, Wakayama shared a cell with Waichirō Sekiya and another inmate. When Sekiya poisoned their third cellmate, he dismissed Wakayama’s survival as mere yakuza luck—a testament to the boss’s perilous existence. Later, Wakayama murdered a tattooed convict, flaying the skin to settle a gambling debt in Barato. Though entangled in the hunt for coded tattoos linked to Ainu gold, he dismissed their decipherability, citing threats like roaming bears or environmental decay.

A formidable swordsman, Wakayama battled adversaries and beasts alike, yet his defiance of nature proved fatal when a bear ultimately claimed his life. Loyal to his subordinates and ruthlessly pragmatic, his influence stretched from prison intrigues to Barato’s underworld, etching his legacy into the bloody saga of the tattooed skins and their buried fortune.