Kawasemi Omito, a supremely skilled detective, leads a joint investigation into a serial killing case. Amamiya lends him Toto, whom Kawasemi deems so useless he's invisible. Ron appears at the newest crime scene as a consultant, irritating Kawasemi.

Toto meets Kawasemi while on a business trip to Aichi. Kawasemi's been in a slump since losing Yamane, and his powers of perception have suffered. He's investigating the Mad Chameleon, who commits a crime right in front of them!