Ryou is a normal student, but one day he awakes in the morning and discovers... That he had transformed into a Girl from night to morning!!

His sister will try to get him to get back to his previous self.... but the experiment fails and he is unable to come back to be a men.

Now he will start living as a woman, but... will he be able to comeback to his previous self, or when he would be able to do it he won't want it anymore...?