Dusk Maiden of Amnesia(黄昏乙女×アムネジア)

Dusk Maiden of Amnesia revolves around a first-year high school student, Teiichi Niiya who had just enrolled at Seikyou Private Academy. One day while wandering the hallowed halls, he gets lost in one of the school's old buildings and encounters Yuuko Kanoe, who reveals herself as a ghost with no memories. While investigating her death by looking through the school's seven mysteries, they discover the truth about these ghost stories and help those who are troubled…