Dusk Maiden of Amnesia

Dusk Maiden of Amnesia (黄昏乙女×アムネジア, Tasogare Otome × Amunejia) is a Japanese manga series, written and illustrated by Maybe. It was published by Square Enix and serialized in the Monthly Gangan Joker magazine. An anime adaptation by Silver Link aired between April and June 2012. It has been licensed by Sentai Filmworks in North America.

Plot
The story revolves around a first-year middle school student, Teiichi Niiya who had just enrolled at Seikyou Private Academy. When he gets lost in one of the school's old buildings, he meets a girl named Yuko 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 Yuko discover the truth about these ghost stories and help those who are troubled.