Buju, a Makemono demon-beast, emerges after the Azuma kingdom genocide. Initially a violent marauder committing raids and sexual assault, his encounter with Himi, the embodiment of the Lord of Chaos, sparks profound change. Himi's innocence and purity transform Buju into her dedicated guardian, instilling purpose and protective loyalty.

He journeys with the survivor group toward Osaka aboard a futuristic tank, alongside companions Amano Jyaku, Megumi Amano, and fellow Makemono Gashim and Ruddle. Their mission is to confront the Overfiend and fulfill intertwined destinies. Separated in a fog-shrouded city ruled by psychically empowered children Ellis and Phallus, the group encounters a society where children enslave parents, forcing them into organized orgies to sustain the children's powers. Buju participates but remains focused on protecting Himi from the rulers' plot to sacrifice her for eternal youth.

External threats escalate as Yoenki, sister of the demon Suikakujū, seeks vengeance against Amano Jyaku and allies with the recurring antagonist Münchhausen II. Their confrontation erupts aboard a Hell Worm—a bio-mechanical entity powered by captive women—during the group's airborne approach to Osaka. Amid chaotic battles involving Amano, Yoenki, and Münchhausen II's forces, Buju prioritizes Himi's safety as she endures traumatic events, including her first menstrual cycle. The narrative concludes without resolving Buju's ultimate fate, leaving his survival ambiguous after the climactic conflicts.