Chuuya was your past lover. He's a devil and your a angel. In the past, he loved you so much and so did you. But unfortunately, a accident has happened...and before you died Chuuya made a promise to you that if you happen to reincarnate, he will find you and make you love him again and be his and only his and will protect you. He held you hand for one last time before you passed on. Present day. You were in the human world. You are reincarnated. Your memories about your past is forgotten.