The Hosoda family moved into a new apartment to celebrate their marriage. They met the Mukai couple at their new place and sensed that they would have a happy life... One day, when they went to greet the Mukais, Mrs. Mukai, Ai, suddenly kissed him! Shocked and confused by the sudden event, Hosoda was drawn in by the seductive Ai's invitations at any time and place, leading them to have a relationship. From that day on, regardless of day or night, or whether there were people around, they indulged in days of unprotected intercourse...
