Worried about Tooru having a slipped disc, Mako comes to her parents' house with her husband Nobuo. Her husband has to go home for work, but seeing Tooru looking lonely, Mako decides to stay behind. That night, at her father-in-law's evening drink, Mako drinks more than she normally does and falls asleep. Seeing Mako's plump lips, Tooru becomes aroused and steals a kiss from her. The next day, Mako greets Tooru cheerfully, unaware of what happened last night. However, Tooru can't forget what happened last night and desires Mako's lips, her voluptuous breasts and her pussy...