My-Otome (manga)

Arika Yumemiya has traveled far in search of her goal: the prestigious Gualderobe Academy. This is the school where young girls are trained to become Otomes, protectors of royal leaders throughout the lands. Here, Arika makes plenty of friends, but some enemies know something about her past that she does not. Nevertheless, her spirit and determination will keep pushing her forward

Mashiro-hime has just transferred to the all-girls school, Garderobe...but little do the other students know, she's actually a boy. Desperate to escape an all-boys school where he was looked down upon, he disguised himself as the late Mashiro-hime to get in. Unfortunately, due to "her" royal status, members of an organization known as Shwarz are trying to assassinate him, and all the while, he's trying to break his Contract with Arika Yumemiya, who unexpectedly became his Otome to protect him from a member of Shwarz.