Kakuriyo no Yadomeshi

Female college student Aoi inherited her deceased grandfather's ability to see ayakashi. One day, while Aoi is feeding some ayakashi, a demon appears! He declares that Aoi's grandfather owed a great debt, and as compensation, Aoi must marry the demon! Aoi refuses, and decides to pay off the debt by working at the inn of the afterlife, the Tenjin-ya.