Dusk Maiden of Amnesia (2012)

The story revolves around a first-year high school student, Teiichi Niiya who had just enrolled at Seikyou Private Academy. When he gets lost in one of the school's old building, he meets a girl named Yuuko Kanoe who reveals herself as a ghost with no memories. Teiichi then decides to investigate her death by looking through the school's seven mysteries revolving around her. Throughout the story, Teiichi and Yuuko discover the truth about these ghost stories and help those who are troubled.