Des:Mr. and Mrs. Hatano have moved to the lower floor and come to greet Mr. and Mrs. Otsuki who live on the upper floor. The moment the Otsukis saw the two of them, the desire within them was awakened. After confirming that Yuis girlfriend was absent, Hibiki stormed into Yuis home and succeeded in seducing Yuis husband. Hibiki enjoys sex with her husband and her husband Yui, and one day she invites Mr. and Mrs. Hatano to dinner at the Otsuki house and reveals her relationship with Yuis husband. Yui finds out about this and ends up having a relationship with her girlfriend Otsukio. What is the relationship between husband and wife...