Hamekoi!

Most people have a secret they just can't tell others. In my case, I have two. One is there's someone I like. And the other is... I am crossdressing while attending an all-girls' high school. I, Mizuki Saiki, have an older twin sister named Miyuki: and to suit her own purposes she is practically forcing me to crossdress, so that I can attend her all-girls school as a female student in her place. "But this way, I can stay together with my beloved childhood friend Kaya-chan... as long as I don't get found out!" Desperately trying to hide the fact that I'm a boy amidst nothing but girls... A comedy about a heart-pounding mission that's swirling with ulterior motives! (Source: Square Enix, translated)