Otone is a normal boy, but his family is anything but normal. The day before he was to transfer into Fujimi Gakuen, his older sister Otona said that she was tired of being a girl and switched bodies with him using the ‘mind change’ special ability. Meanwhile, Kanade wanted to join the band club since she loved the band’s performance during the town’s Christmas Festa when she was small. However, the band club has been closed and she sets out alone to find people to join the club. That’s when she bumped into Otone (♀) and gets him (her?) to join the band.