Kaoru meets Kudou on his way to work. Kudou is on her way to the scene of the murder to investigate. By following her request, Kaoru starts to investigate the murder case with her, and they find another dead body hanged from a tree soon after. According to people living nearby, a hanged dead body is found every year around the annual festival. They treat it with care as a sacrifice to Tsukutori, the local deity. Kaoru and Kudou don't believe it, but they face a series of mysterious accidents...