Agasa takes the Detective Boys with him to a sauna as he fixes his product. At the sauna, the kids are introduced to four cast members filming a drama about a hitman. Since the sauna is crowded, the kids decide to bathe in the early morning. As they head to the sauna, Ai and Ayumi discover the Ganji Tetsuyuma, the scriptwriter, dead. The police arrive and conclude that Tetsuyuma slipped on a bar of soap and hit his head on the rocks.