Fukigen Cinderella

A man named Haruhiko Kanna lives a normal life until he encounters three witches in a room inside an old clock tower. As a result, he is given a strange transformation: he becomes a girl at 12 Noon and reverts to his male form at 12 Midnight. He begins to wonder how long this will continue, whether he can cope with the changes, and if there is any way for him to return to his usual self.