Akito and Ruriko are in their fifth year of marriage. One day, Ruriko is suffering from stiff shoulders, so Akito brings her a flyer for a chiropractic clinic. She immediately goes to the clinic on her day off, accompanied by Akito, and for the first time, she feels aroused when a man other than her husband touches her body. Noticing Ruriko's change, the chiropractor, Oki, begins to fondle her aching genitals during her second visit. Though she thinks, "I should stop seeing him," she still finds herself touching Oki's penis...