Rikuo Nura is the grandson of Nurarihyon, and thus the Third Heir of the Nura Clan. However, being three fourths human, he does not act like the third heir. All of the yÅkai of the Nura Clan want him to assume the leadership, but he just wants to be a normal human. His classmate Kiyotsugu invites Rikuo to come with them to the old school building that is said to be haunted by yÅkai. They set out to investigate whether the building is really haunted by yÅkai or not.[4]