The Nezumi-sou Dormitory, also known as the Fourth Dormitory of Rat Production, is home to dropout idol girls. Among its residents are former child actor Sekino Roko, musician Nukui Hayu, and model Maehara Nina. Sakura Ino, who has always dreamed of becoming an idol, also moves in. However, the decision is made to demolish the dormitory due to a project launched by its manager Kajino Hoho called "Ochikobore Fruit Tart." As a result, the occupants form a new idol group named "Fruit Tart" with the goal of repaying their one hundred million yen debt.