Mikio Shirato, older brother of Yukiko Shirato, is a scientist dedicated to research and development within the world of Megalo Boxing. Initially introduced as a strategic rival to protagonist Joe, he engineered AI-powered combat gear to challenge him in their first-season showdown. His defeat in this high-stakes match prompted his retirement from competitive boxing, leading him to pivot toward academia as a university professor while maintaining his scientific pursuits.

Mikio’s expertise lies in technological innovation, exemplified by his self-designed Ace gear—a landmark advancement in combat equipment that pushed the boundaries of the sport. His retirement marked a deliberate shift from athletic rivalry to shaping future advancements through education and R&D, though the precise scope of his academic contributions remains unexplored.

His rivalry with Joe centers on their opposing philosophies: Mikio’s methodical, tech-driven approach clashes with Joe’s raw, gearless instinct, framing the series’ core theme of human tenacity versus technological enhancement. Though his post-retirement role recedes from the spotlight, his enduring presence subtly anchors him to Megalo Boxing’s shifting dynamics, reflecting the sport’s ongoing interplay between tradition and innovation.