Mitsuki Kanzak is forced to move in with her stepbrother Yuuya due to her mother remarrying. One day a spirit named Hiyori Kotobuki possesses Yuuya's sister's body. The goal of this ghost is to fall in love with Yuuya in order to have the gates of heaven to open up to her. The catch is this must be done while she is in Mitsuki's body.