Onoe, a housewife, is haunted by a past strap-on rape nightmare. Aoi, a sales clerk at a pharmaceutical company, finds clues about the rapist, saying that she is "a woman with a tattoo on her chest" from her story with Onoe. One day, Usui, an insurance company employee, forcibly steals Aoi's lips when she comes to work, but she escapes on the way. At that time, Aoi saw a "tattoo" on Usui's chest. Convinced that she is the culprit, Aoi unites with her Onoe and puts her revenge strap-on into Usui, but she falls for Usui's scheme and this time Ao falls prey to the aphrodisiac strap-on...
