Natural High boldly approaches girls walking through hot spring towns, offering cash and asking, "Won't you join me in a mixed-gender bath?" While the world isn't so kind that money is easily earned just for entering a bath, things gradually escalate—under-the-surface touching turns into full-on fucking. The thrill of these encounters, sometimes happening while other guests are present, creates a unique atmosphere vastly different from the hustle and bustle of city life.