Hiroshi Haoka reigns as a feared delinquent at Reverse Cross High School in a post-apocalyptic world. His deep-rooted childhood bond with Tsumiko Horie fuels a fiercely protective nature, driving resentment toward anyone displaying romantic or predatory interest in her. This protectiveness sparks his initial hostility toward Kakugo Hagakure, the series' protagonist, following Kakugo's arrival and interactions with Horie. However, witnessing Kakugo's actions transforms Haoka's view, shifting his antagonism into demonstrated respect. During the decisive confrontation with the Tactical Fiend Eikichi, Haoka intervenes directly, transporting Kakugo's critical combat armor, the Fortified Armor Shell Zero, to the battlefield. Eikichi's attack during this action inflicts severe injuries on Haoka, yet he survives and is confirmed alive at the conflict's conclusion. He is frequently seen alongside his associates, Ponta Takada and Pyonsuke Fuji. His narrative development centers on his evolving dynamic with Kakugo and his survival in the OVA events.