The Day of Revolution Vol.1 (2006)

Kei Yoshikawa is a feisty young boy, troubled by problems at home and annoyed at school. One day after a sudden fainting spell, Kei is examined by the doctor and given shocking news - he is actually supposed to be a girl! Although physically male, Kei's chromosomes show that "he" is female. Seeing a chance to start life anew, Kei and his family decide to have him begin living as a girl. As "Kei" disappears and "Megumi" enrolls back into school, his/her girl pal Makoto is Kei's only ally who knows his secret. Dressed like a girl but still feeling like a boy, mixed-up Kei/Megumi feels more comfortable being with Makoto than the other boys... What's a gender-confused kid supposed to do?