Ruri Ginjō, a determined 15-year-old junior high student, steps into the role of owner of the Silver Castle sports team after inheriting it from her father, Ricardo Ginjō, whose sudden disappearance was initially deemed an accidental death. Unraveling the truth, she discovers Ricardo faked his demise to evade persecution for resisting military technology development, including Shock Circuits—devices designed to control robots. Concealed within Silver Castle’s basement, he avoids retribution while clinging to his ideals, forged during his tenure at Dark Prince’s research institute where he engineered the legendary robot Magnum Ace, once named Silver Frontier.

Leading Silver Castle with unwavering resolve, Ruri champions her father’s principles of fair play, staunchly rejecting violent tactics despite competitive pressures. Outwardly buoyant and motivational, she masks private struggles with loneliness, channeling her grief into collaboration with Coach Eddie Ginjō to nurture team unity and ethical play in a league riddled with corruption under Chairman Hiroshi’s ironclad control.

Her relentless pursuit to uncover Ricardo’s whereabouts fuels both personal healing and Silver Castle’s crusade against the Shock Circuit system. This dual mission galvanizes allies, strengthens team bonds, and sparks a broader movement to dismantle systemic dishonesty, weaving her journey of loss and reconnection into a larger tapestry of resistance—cementing themes of perseverance and moral courage as Silver Castle challenges a rigged world.