Mika Kato operates as a member of the Sailor Victory superhero team defending Mikado City on the planet Tatsu Asuka. By day, she works as a delivery girl for Choju-An Delivery Service, serving clients such as the Central Police Force. Within the team, Mika exhibits a notably calm and rational demeanor, setting her apart from Kiyomi's temperament, Mami's clumsiness, Reiko's eccentricity, and Shizuka's sharp tongue. She pilots the blue Momoyama mecha during missions and frequently asserts leadership among the three primary field operatives. However, Mika, Kiyomi, and Mami all make similar claims, resulting in no single designated leader. Mika displays a competitive streak in combat, showing subtle frustration when not first to engage enemies and openly taunting adversaries when gaining an advantage. Her interactions with teammates include moments of friction, like expressing reluctance to babysit Mami. She confronts threats orchestrated by Queen Margarita, battling criminal robots and Margarita's giant magical robot.