Kayo, a young Japanese doctoral student in art history, is an involuntary witness of a ruthless execution. She casually runs into Coliandro, who decides to protect her and hide her at her house with Kenzaburo, her brother. The man, who arrived from Japan in defense of his sister, is a former repentant of the yakuza, the fearsome Japanese mafia, which is hunting them.

Coliandro seems to be on the verge of positively concluding a gallant adventure. But, at the climax, Giacomino shows up at his house, sleepy, hungry and with handcuffs on his wrists. The motivation is incredible: Giacomino is accused of being the author of a series of brutal murders. To help his friend, Coliandro will have to hunt down the real serial killer.

Coliandro is forced to be Paffoni's dance partner for one evening. To escape the thankless task, he finds himself investigating the murder of a young singer. To help him there is not only Paffoni, an experienced dancer, but also Natascia, the new young and beautiful singer of the smooth orchestra led by the shady Vasinto and his wife Ersilia called "Vagona".

At the Questura Coliandro meets Asmareth, a young and beautiful Eritrean cultural mediator who works for the police. Believing her to be an illegal immigrant, Coliandro puts together one gaffe after another. To make up for it, he agrees to help her in a research that the girl is doing on illegal work. Coliandro and Asmareth thus unmask a gang that organizes "manhunts" for bored provincial rich people.