Rookie detective Izumi Sakuragi investigates a mysterious box containing the skeletal remains of a teacher who went missing 11 years ago. The sender is identified as one of the teacher's former students, now comatose after a fall. As the other former students remain silent, Izumi finds a clue in the astronomy club's old diary. A necklace made of a special material is found at the burial site, and with the help of a cryptic blog message, Izumi gets closer to the truth.
