Detective Kamiya becomes the new victim. Since his belongings are taken, Shota thinks that Kamiya may have had information that could lead to the murderer.
Guessing Kuroshima's stalker, Uchiyama, may have been bugging Kuroshima's room, Shota raids Uchiyama's place. Shota finds a disturbing and shocking confession that Uchiyama made by video prior to his death.
Minami suspects Tamiya is the killer of a five-year-old unsolved murder case and questions him. Shota enters Minami's unit and upon seeing a large number of documents in the room, realizes something is up and rushes out of the place.
Kuroshima is likely to be the mastermind of the murder game based on the AI analysis. Shota finds a new clue from the puzzle Nana left, and decides on a plan to lure the mastermind out of hiding.