Celebrity Fit Club is a reality television series that follows eight overweight celebrities as they try to lose weight for charity. Split into two competing teams of four, each week teams are given different physical challenges, and weighed to see if they reached their target weights. They are monitored and supervised by a team that includes a nutritionist, a psychologist, and a physical trainer, the latter of which is former U.S. Marine Harvey Walden IV.

Hibiki Sakura is your average high school girl, with a voracious appetite. Noticing her clothes tightening in lieu of her slowly expanding waistline she decides to look into enrolling in the nearby gym. There she runs into a girl from her grade named Souryuuin Akemi.

Akemi, who has a muscle fetish tries to get Hibiki to enroll in the gym despite its high ratio of macho men. Thankfully a beautiful trainer, Machio, appears and unknowingly convinces her to enroll and start her quest to a great body.