The year is 2120. AI technology has advanced to the point where humans can live a rich life without having to work much, as robots can do everything for them. Haruna and Natsuki, a newly married couple who are very much in love, introduce the latest humanoid helper AI robot, "Otetsu-kun," into their home. On the first day of his arrival, Otetsu-kun notices Haruna's frustrations and helps her satisfy her sexual desires when Natsuki isn't looking. At first, Haruna is reluctant, but before long, she becomes honest with her desires and falls into depravity in both body and Kokoro...