Boss emerges as a young delinquent within the Mazinger Z series, primarily delivering comic relief. Initially a schoolyard bully and rival to Kouji Kabuto, he gradually transitions into an ally, scouting for Mazinger Z on his motorcycle and engaging in slapstick antics. His original gang members are Nuke and Mucha, expanding in *Great Mazinger* to include Bakarasu and Kouji’s brother Shiro. He shares a longstanding friendship with Sayaka Yumi and nurses a significant romantic attraction toward her. Midway through *Mazinger Z*, Boss and his gang uncover an abandoned warehouse stocked with scrap materials. They kidnap scientists from the Photon Power Research Institute, coercing them to build a giant robot from the junk. This results in Boss Borot, a comically inept machine piloted by Boss. His cousin Misato, a former model, later joins the Photon Power Laboratory, handling domestic chores like cleaning and cooking—a stark contrast to Sayaka’s demeanor. In *Shin Mazinger*, Boss’s role diminishes. Portrayed as Japan’s overarching delinquent gang leader, he travels to leaderless Atami and targets Kouji Kabuto as the area’s strongest student, aiming to defeat him for dominance. An Ashura Corps attack interrupts his scheme. Subsequently, Boss and his gang rack up massive debts from extended spa stays, forcing them into labor at Kurogane House. They also operate a construction robot for the Photon Power Labs, which later inspires a new Boss Borot iteration. Throughout, Boss sustains a friendly rivalry with Kouji, occasionally aiding him in combat. During the crossover film *Grendizer, Getter Robo G, Great Mazinger: Kessen! Daikaijuu*, Boss pilots Boss Borot against the Dragonsaurus, a colossal sea monster besieging Tokyo. His intervention backfires when the creature swallows Boss Borot whole. Internal oil from the robot causes the Dragonsaurus to grow larger and stronger, hampering the primary mecha. Great Mazinger wounds the monster, ejecting Boss Borot from its body. Boss features sporadically in *Grendizer* and ascends to a main role in the *Mazinkaiser* OVAs. There, he battles Doctor Hell’s forces alongside Kouji using Boss Borot, now depicted in an upgraded form that maintains its status as a secondary combatant in the Mazinger universe.