High school student council president Hotaru Tachibana—a girl often confused as a boy due to her speech pattern and clothing—is not afraid to fight against injustice. When her friend is supposedly swindled by a host, Hotaru feels compelled to confront the man responsible. He turns out to be her next-door-neighbor, Masamune Matsuoka, who decides that the best way to settle this is to play a "survival game": an imaginary war game where fake guns are used, but the battles are no less real. Despite Hotaru's best efforts, she ends up losing and incurring a large debt due to the resulting damages. Consequently, she is forced to become the third member of Masamune's male-only team "Toy ☆ Gun Gun," joining his friend, Tooru Yukimura, an author of adult manga who dislikes her at first. However, be