AKA Boku no Itoshii Youkai Girlfriend
The extraordinary Japanese folklore of 'Yokai' and 'Otaku', as a strange relationship of love and mystery is sparked between a lonely college student Tadashi who wants nothing more than to find a girlfriend, and Izzy, a Yokai girl who accidentally finds herself bonded to him through a magical hex. But the quirky love story takes an unexpected and gripping twist as the true intention of Izzy is to exact revenge on a human family for an incident from over 500 years ago.
Note: This show is in Japanese Language but with hardcoded English Subtitles.