A prostitute from Hananoya, O-Taki, has been killed. When Takuboku says, "I saw Kyousuke in O-Taki's room," Kyousuke becomes a prime suspect. Meanwhile, based on the fact that Takuboku's romaji diary was left in O-Taki's room, Kyousuke begins to suspect that Takuboku might have done it. Where does the truth really lie?