The Metropolitan Police Department is struggling to investigate a series of murders, yet Detective Isshiki is ordered to go home. Kiku of the General Affairs Division sends him to meet a certain sleuth—a shaggy-haired eccentric named Kamonohashi Ron.

Ron wins a pair of tickets to a hot spring in a raffle. Toto accompanies him to stay at the Benizome Inn. The innkeeper who greets them is friendly, but he isn't who he seems. Plus, it isn't long before Ron's eccentricities begin to surface.

Depois da descoberta do corpo da mulher no banho feminino, Amamiya é a primeira suspeita por não contar com um álibi na hora da morte. No entanto, Ron... Ou melhor, Isshiki apresenta provas que podem virar o caso totalmente.

Kawasemi, um inspetor de grande renome, vem de Aichi para resolver um assassinato em série. Amamiya coloca Isshiki para trabalhar com ele nesse caso, em que o assassino corta e leva as mãos de suas vítimas.

Depois de viver muito tempo isolado do mundo, evitando assim o contato acidental com algum caso, Ron está viciado em programas de televisão. Parece que sua antiga cautela não era em vão, já que ele acaba assistindo a um assassinato ao vivo em sua atração favorita!

Isshiki leva Ron para ver a chuva de meteoros a que foi convidado. No caminho, ele descobre que foi convidado por indicação do Kawasemi. Anos atrás, houve um incidente nesse mesmo observatório, então o diretor resolveu chamar um inspetor de polícia e um detetive para o evento por garantia.

Ron is named main suspect in a murder and Toto investigates to clear his name. Everyone but Ron has an alibi for the time of the murder, which only seems to cement his guilt, but Toto discovers a few things that cast a new light on the incident.

Toto gathers everyone together and explains the truth behind the murders. With their name exposed, the culprit takes drastic measures not to be caught, but not before revealing that there's more to this incident than anyone imagined.

Toto is shadowed by a reporter who's a huge fan of his for the way he's solved one difficult case after another. They step into a cafe where Ron happens to be working, making things a little awkward. Then, a customer collapses to the ground—poisoned!

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!

Ron agrees to take on Spitz's search request in exchange for his obtaining a file on the Bloody Training Incident. Spitz accepts Ron's terms and takes Ron and Toto to Yadamura, a village in Yamanashi prefecture where his ethnologist brother disappeared.

Toto reveals the truth of the case and the culprit admits to their crimes. Ron's disorder triggers, putting the culprit in danger, but help comes from an unexpected source. Who is their last minute savior, and how are they connected to everything?