Buju emerges as a violent, hedonistic demon-beast, his early existence defined by raiding, pillaging, and acts of sexual brutality. His atrocities culminate in the slaughter of a family—infant included—and the violation of their surviving teenage daughter, irrevocably cementing his moral depravity. This brutality crosses a Moral Event Horizon, branding him a figure of irredeemable cruelty.

A partial shift follows: Buju aligns with Himi, the Lord of Chaos, becoming her protector and aiding her quest to confront the deity Chōjin. Yet this redemption remains superficial. His callousness persists, and self-gratification consistently overrides altruism.

Traveling to Osaka, his group encounters a city ruled by psychic children who enslave adults in forced orgies. Buju indulges in the debauchery rather than opposing the exploitation, his moral ambiguity laid bare. When implored to rescue Yumi, a victim of demonic assault, he openly admits to relishing the violence inflicted on her, underscoring his enduring absence of empathy.

His past includes enslavement under Caesar, a tyrant who imprisoned and exploited demon-beasts. After escaping, Buju joins a band of survivors navigating a post-apocalyptic wasteland. Fleeting camaraderie with figures like Gashim and Idaten surfaces, yet these bonds fail to dilute his self-interest.

Later conflicts against antagonists like Münchhausen II and Yoenki cast him as a conflicted antihero, his actions vacillating between self-preservation and reluctant heroism. However, his history of atrocities and ongoing moral failures bar full redemption. His unresolved arc mirrors the narrative’s exploration of cyclical violence and the precariousness of absolution in a morally corroded world.