is a Japanese light novel series written by Yuyuko Takemiya, with illustrations by Eji Komatsu. The series includes 11 novels published by ASCII Media Works between September 2010 and March 2014, and incorporates romantic comedy and supernatural themes. A manga adaptation by Umechazuke began serialization in the October 2011 issue of Dengeki Daioh. A 24-episode anime adaptation by J.C.Staff aired on MBS between October 2013 and March 2014.