Da-hyeon and Hyeon-soo grew up like sisters without their parents, and still live together even after Da-hyeon got married. Sex isn't good between Da-hyeon and her husband, so when her husband is out, she has an affair with a stranger.  One day, Hyeon-soo's step-father, Seok-hyeon, goes to his son's house and sees his son's wife's sister there all by herself...

Gelin 2

Yeong-soo saved money for 10 years since he graduated high school and now he's getting ready to go to college, which he has been putting off. Ji-eun is his girlfriend who has been by his side for the last 5 years, but the sex with her is quite boring. It almost feels like a chore. However, he doesn't want to break up with her, as they have been together for a long time.  The first mock test comes up, but Yeong-soo has lost his will to go to college and his sexual desires.

Extreme Lesson

Seong-il and Hyun-jung are a couple. Seong-il loves sex. However, Hyun-Jung is fed up with the sex demands of Seong-il who is too obsessive. Hyun-jung talks with her senior about her husband's complaints. Minwoo, who lives next door, comes outside and accidentally listens. Minwoo, who was usually interested in Hyunjeong, pretends to be a coincidence and helps Hyunjung to throw away the trash. Min-woo, who is favored by Hyun-jung, asks sex partner Yoon Kyung to twist her. Disguised as a gas inspector, Yun Kyung visits Seong-il's house and seduces Seong-il to succeed. After that, Sung-il tries to have sex with Hyun-jung, but Seong-il...