Mei no Naisho by Kusaka Shiroi is a shonen (?) manga about a guy raised as a girl who attends an all-girl's school after his only family, his mother, dies. He has no idea he is a girl until it is discovered during the obligatory bath scene. Luckily he is allowed to stay because he's obviously so harmless. He's also a witch with a familiar cat. In any case, Mei is very feminine and demure, making him seem more girly than the real girls. His roommate is a tough girl that other girls look up to. She watches out for him to the point of being overprotective, but also keeps having hilarious nose bleed incidents when he is shown in compromising positions. Though totally improbable, it's amusing to see the role reversal of the genders. There's also an ecchi student council president (female) who likes to dominate the other students.
I doubt this manga will amount to much, but the first volume was amusing enough.
One scene where tough roommate has a nosebleed moment.
Tough roommate is against Mei working part-time at a maid cafe because she is so innocent she may fall for some customer who turns out to be an alien! Talk about insane.