Onoue, a housewife, is haunted by a nightmare about a strap-on in her past. - Ao, a salesperson for a pharmaceutical company, finds clues about the rapist, ``a woman with a tattoo on her chest,'' from a conversation with Onoe. - Usui, who works for an insurance company, forcibly snatches Aoi's lips when she comes to work one day, but she runs away midway. - At that time, Aoi saw a ``tattoo'' on Usui's chest. - Convinced that he is the culprit, Aoi unites with Onoue and puts a revenge strap-on on Usui, but he falls for Usui's plan and this time Aoi falls prey to the aphrodisiac strap-on.