Fukigen Cinderella Manga Summary
From Pinoymanga Scans (with grammar edit by Lynkz):
Haruhiko Kanna is just an ordinary man with an ordinary life. One day he meets 3 witches in a small room in the old clock tower, and that's when his ordinary life became not so ordinary at all.
With the curse, or gift, he was granted that he'll change to a girl once the clock strikes 12 Noon, and will return to his male self at 12 Midnight. He then asks himself, What on earth will happen if this goes on? Can I survive like this? Most of all will I turn back to normal again?!