During a regular after-school grub crawl, gluttonous high schooler Hibiki Sakura is confronted by her best friend, Ayaka Uehara, about her ever-expanding waistline. With her attempts at solitary exercise failing miserably, Hibiki joins the newly opened Silverman Gym. Hibiki runs into student council president and school idol Akemi Souryuuin at her orientation.

However, it soon turns out Hibiki is in for much more than she bargained for. Not only is Silverman Gym a total of world-renowned bodybuilders and athletes, but to make matters worse, Akemi turns out to be a total muscle fetishist! Grossed out by the scene unfolding before her eyes, Hibiki begins to leave, only to be stopped by trainer Naruzou Machio. Completely enthralled with her newfound Prince Charming, Hibiki signs up as a gym member. Due to her spur-of-the-moment decision, Hibiki must adapt to her new lifestyle.