Mizuho Miyanokouji

Mizuho Miyanokouji, from Otobuko, is a shy boy who often hides behind his childhood friend, Mariya. According to Mizuho's Grandfather's Will, he must attend an All-Girls School. So he must cross-dress to remain undetected, with the aid of Mariya. Briefly he becomes an actual girl after being possessed by the ghost girl living in his dorm, though this only happens in the manga and the visual novel.