Miki Jounouchi is the chief mechanic for the Sugo racing team, responsible for vehicle maintenance and pit stop operations, including tire changes during races. She possesses a tomboyish personality and an interest in rock music. Professionally dedicated, she engages in technical preparations alongside other crew members. She was aware of driver Naoki Shinjyo during his Formula Three career, admiring his determined driving style and competitive spirit. This professional respect later evolved into a personal connection as their relationship developed. Throughout the series, she remains consistently involved in the team's technical operations, focusing on vehicle performance optimization and race strategy support from the pit area.