In the near future, robots have become a part of society. An accident occurs when a bank security robot suddenly goes out of control. Takizawa Yuu, a forensic scientist who was on the scene, stands helpless before the mighty power that has lost control and gone berserk... Then the Metropolitan Police Department's special robot unit, SARF, arrives. The mobile investigator who buddies up with SARF's all-powerful cyboroid Redo is Yuu's older brother, Takizawa Shou...