Tachibana Hotaru (voiced by Komatsu Mikako) is a girl with a strong sense of justice. One day, she moved into the Tsukishiro Apartment and prepared to start a life alone. What Hotaru, who lives in Room 202, didn't expect was that a gigolo named Matsuoka Masamune (voiced by Maeno Tomoaki) lived next door to her. This frivolous and slick man didn't leave a good impression on Hotaru. Yajima Ding (voiced by Horie Yui) is Hotaru's only friend. One day, Ding told Hotaru that he had been cheated of all his savings by a gigolo, which made Hotaru indignant. Hotaru rushed to the gigolo shop to find the gigolo who cheated Ding and seek justice for his friend. However, to Hotaru's shock, this gigolo was none other than his neighbor Matsuoka. In the face of Hotaru's provocation, Matsuoka actually proposed to use a gun to decide the outcome. In this way, Hotaru was involved in a survival game of fighting for each other.