A murder case is reported in which drugs are believed to be involved. From the conditions at the scene and the remains on the victim's clothes, it becomes clear that flour is involved in the case. Seiya, who uses his famous tongue to recognize the flour as okonomiyaki flour, goes to several okonomiyaki restaurants in the vicinity of the crime scene and notices the murderer at one of them. He realizes that the culprit is in one of the restaurants. Eventually, Seiya, Ryosuke, and Kyoko are trapped by someone and locked in a warehouse, where they find a time bomb with 10 minutes remaining... When they fail to disarm the time bomb, they find themselves in a desperate situation!