Manga: Dark Gathering (volume 7)

Before they can tackle their next haunted site, Keitaro, Yayoi, and Eiko need to collect another of the sealed Graduates—a vengeful courtesan who’s eager to escape Yayoi’s control. However, things turn even more dangerous when Keitaro is drawn into the spirit world, forcing him to face the horrors of a haunted love hotel all on his own.