Hibiki Sakura and Ayaka Uehara are walking home from Koyo Women's Academy when Ayaka notices that Hibiki has gained weight and suggests that she should go on a diet. A week later, Hibiki heads to the Silverman Gym. Inside the gym, she notices that Akemi Soryuin, a schoolmate, wants to join too. They look at one of the training rooms and notice that all of the members are buff, which causes Akemi to instantly join. When Naruzo Machio, one of the trainers, introduces himself to Hibiki, she joins as well...