Hibiki Sakura, a gluttonous high school student, is confronted by her best friend, Ayaka Uehara, about her expanding waistline during an after-school grub crawl. Hibiki attempts to exercise alone but fails, leading her to join the recently opened Silverman Gym. Despite running into the school idol and student council president, Akemi Souryuuin, at her gym orientation, Hibiki soon realizes that the gym is full of world-renowned bodybuilders and athletes. To add to her dismay, Akemi is revealed to be a muscle fetishist, which grosses Hibiki out. As she tries to leave, trainer Naruzou Machio stops her, and Hibiki instantly falls for him, signing up as a gym member. As a result of her impulsive decision, Hibiki must now adjust to her new lifestyle.