Satou Tatsuki, a class troublemaker, gets his motorcycle license and takes his genius best friend, Morisawa Kai, for a ride. They get into an accident and Morisawa dies instantly. However, Morisawa wakes up at the hospital inside the body of a girl who was taken in for alcohol poisoning. His relationship with Tatsuki begins to take on a whole new level as he deals with the changes in his body and other soul which inhabits it.