Kozo Shiranui, performing under the stage name Seijūrō Yuyama, travels with the Yuyama Troupe after narrowly escaping execution—a fate averted when playwright Sotetsu Ibaragi intervened with a strategically staged production. His past unravels a grim betrayal: accused of murdering a policeman’s wife with whom he shared a clandestine affair, he was framed by the grieving husband, who took his wife’s life before ensuring Shiranui faced the blame.

Known for his breezy disregard for convention, Shiranui frequents red-light districts, a habit contrasting his deepening affection for Kotoha, a respected courtesan in Yokohama’s pleasure quarters who aids the troupe. Their connection weaves personal stakes into his loyalty to the group, though their romance remains constrained by the troupe’s collective ambitions.

As an actor, he channels his fugitive history into performances that mirror the troupe’s vengeful pursuits—targeting those who orchestrated their leader’s familial tragedy. While camaraderie and a tenuous redemption bind him to the troupe, his actions pivot on survival and allegiance, his past a shadow beneath the stage lights. His story unfolds solely within the main series’ narrative, untethered to expanded media adaptations.