Originally a delinquent student and rival to Kouji Kabuto in Mazinger Z, Boss eventually became an ally. He commanded a gang featuring Nuke and Mucha. During the latter stages of Mazinger Z, Boss and his gang uncovered an abandoned warehouse filled with scrap material. They kidnapped scientists from the Photonic Research Institute, compelling them to construct a giant robot from the junk. This effort produced Boss Borot, which became his personal mecha. Boss continued providing comic relief during his occasional appearances in Grendizer. His character also featured in the Shin Mazinger series, depicted as the supreme leader of all delinquent gangs in Japan. In this incarnation, he traveled to Atami to assert control over the sole region lacking gang presence, leading to fresh confrontations with Kouji. Following an assault by the Ashura Corps, Boss and his gang accrued massive debts at a spa, resulting in their forced employment at the Kurogane House. They occasionally undertook tasks for the Photon Power Labs, operating construction machinery that later inspired new versions of Boss Borot. Boss also appeared as one of the main characters in the Mazinkaiser mini-series.