At a long-established hot spring inn in Beppu City, Oita Prefecture, a couple checks in and opts for the inn's massage service. However, the massage therapists here are unscrupulous practitioners who won't hesitate to seduce any female guest they take a liking to. Regardless of whether the husband is right beside them, they proceed shamelessly—eyeing the husband as he dozes off during the session. An unexpected turn of events awaits.