need help..

there this shoujo that I want to read again but I forgot the name. The story is like this: the Mc is a boy and he is popular. The person he like confessed to him but he rejected her(I think because he want to enjoy it more). His bestfriend love piano and also everyone think that they are gay and they are dating.One day he feels pain in his whole body then he collapsed. When he wokes up he became a girl ,his parents told him that its in the blood.His father is a girl but she became a boy just like him.Because he became a girl they went to another place. Then his bestfriend and the girl he likes thinks that something happend to him because he suddenly disappeared. The girl he likes is looking for him ..Thats all I can remember sorry and Thank you..