Overview
A corpse of a clown is found in a park. Detective Shirataka Amane of Musashino Higashi Police Station begins investigating with rookie detective Uzuka Shinsaku. They find a picture of the victim holding a balloon with the number 1 and the letters TTX on social media which indicates pufferfish poisoning. Shirataka intuitively suspects that this is an incriminating statement done by a serial killer, but Chief Investigator Fukukawa Saeko denies her. Detective Kusano Seiya and other personnel of MPD First Investigative Division join the investigation, then a second murder occurs. Shirataka recalls an unsolved kidnapping and murder case from two years ago that she still regrets.
| Actor | Age then | Age now | |
|---|---|---|---|
 | 38 | 42 | |
 | 44 | 48 | |
 | 27 | 31 | |
 | 60 | 64 | |
 | 38 | 42 | |
 | 50 | 55 | |
 | 75 | 79 | |
 | 72 | 77 | |
 | 48 | 53 | |
 | 56 | 60 |