wife's best friend

Satoko Yoshimura was living a wealthy life with her husband Taku, a securities manager. One day, Satoko's best friend Miki runs away from home, tired of living with her husband. Taku welcomes Miki along with Satoko, but he is immediately captivated by his wife's best friend who has an attractive body. However, unbeknownst to her, when Miki lets loose in front of Satoko and exposes her breasts and thighs, Taku, who has always been a man of unparalleled sex, bulges out his crotch even though he thinks it's no good...