High school student Sakura Hibiki, known for her big appetite, becomes concerned about her expanding waistline and decides to join a local gym. At the gym, she encounters her classmate Souryuuin Akemi, who has a strong interest in muscles and urges Hibiki to join despite the gym's male-dominated environment. Fortunately, a charismatic trainer named Machio steps in and persuades her to sign up, sparking her journey towards achieving a fit and healthy body.