A Dangerous Knife in a Red Dress

Inspector Tokuno explains that a maniacal criminal is seen at aristocratic parties, slashing red dresses worn by women with his knife. In order to go undercover Ken and Aoi, who is to wear the red dress, must pose as a couple at a party held on a yacht. Natsumi and Kachou come to the party a couple as well, while Miyuki and Yoriko are disguised as waitresses. Ken and Aoi dance to blend in with the crowd. A man appearing to be he criminal soon manages to find Aoi, attempting to molest her. As Natsumi and Miyuki come looking for her, Aoi copes to shake him off. After the said criminal has been caught, Miyuki and Aoi exchange outfit, giving Ken the chance to be with Miyuki. When the actual criminal shows up, Natsumi, tries to attack him, only to be sprayed by sleeping gas. Ken, who has also been sprayed, intervenes and restricts the criminal from harming Miyuki. When the criminal almost stabs Ken, Tokuno arrives and defeats the criminal.