Love Death ~Realtime Lovers~

Hiroki Yanase is a young boy whose mother has died a while ago. His father entrusted him with a small inn, but the two do not keep contact. Hiroki goes to school and enjoys the quiet life of an ordinary Japanese teenager. But this changes when a new student named Nanami is transferred to his school. Hiroki soon discovers that Nanami harbors some deep secrets in her past. As their relationship develops, Hiroki realizes that Nanami is not what she seems to be, and discovers a world of supernatural beings that exists alongside ours.

[From Mobygames]