The main character, Hisoka, was an orphan who got raised by Yukitaka, the owner of gigantic company. He was entrusted to Yukitaka's right hand, Daisuke, and got adopted for the sole purpose of becoming bodyguard for his daughter, Orihime. Hisoka was asked to attend the same school as Orihime, but there is one problem, the school he will be attend to is the famous St. Ceral Girls' Academy which only girls attends the school. He has no choice but dress up and pretend to be a girl to be around Orihime. He got into the school and picks Yuki Mikumi as his new name. Orihime who unexpectedly finds out about the identity of Yuki Mikumi, becomes romantically attracted to him. But later, a girl named Masaki Mirei discovered his disguise.