Nakayama Hinako was looking forward to a fun high school life as a girl but on the first day, she bumps into a boy that looks just like her. He happens to be her long lost twin brother named Hikaru. He forces her to go to Shishiku, an all-boys school, in his place and she can’t leave until she becomes the bancho (boss) of the school. Luckily for Hikaru, Hinako is great at fighting since Hikaru loathes it. Meanwhile, Hikaru enjoys going to an all-girls school in her place.