[Machine Translation] Kou Saijo of the "Hell Agency" wins the battle to become the next Demon King, but gives up his position and continues to spend his days with Seiji as his assistant. Then, a series of suspicious deaths occur in the family's old house, and Kou receives a request for his services. The head of the family dies in an accident, and the granddaughter commits suicide, but the client claims that the deaths are a series of murders inspired by the children's poem "The Goldfinch" by Kitahara Hakushu. A distorted family hides the death of a young girl ten years ago. And who is the third goldfish to be killed? This is the fifth installment of the beautiful boy detective's hell-bent casebook.