Hajime Shirogane serves as the Warrior of Martial Arts among ten reincarnated warriors tasked with preventing the resurgence of the Demon King and the Kyouma demons. As former commander of the original ten warriors in feudal Japan, he carries leadership legacy and responsibility into his present reincarnation. His primary abilities center on advanced combat techniques and hand-to-hand martial prowess, distinguishing him from warriors wielding elemental or supernatural powers. He also demonstrates remote psychic observation and communication, enabling distant monitoring and coordination without physical presence.

Initially positioned as a strategic leader, he provides guidance and oversight during the warriors' early confrontations with the Kyouma. His experience and historical knowledge of their eternal conflict bolster the group's initial cohesion and tactical approach. However, his active involvement diminishes significantly as the narrative progresses. Despite being essential to the mission, he becomes increasingly absent from critical battles and operational planning in later episodes.

His role erodes further during the climactic confrontation against Lord Shindigan and the forces attempting to free the Demon King. Unlike other warriors who participate in the final battle—even minimally—he is entirely absent. This absence lacks narrative explanation regarding his whereabouts or status, leaving his ultimate fate and commitment unresolved. No further character development, backstory exploration, or significant actions in other official media beyond the original OVA series are documented.