Yeon-hee, who hasn't changed her hair and isn't ready for the first night, gives sex advice to her friend over the phone and calls her boyfriend over to have sex. Unlike the first time, he is overflowing with libido and visits her office to have sex. Ji-ho is worried about her girlfriend. Although they are friends, Chae-ah and Seon-woo end up having sex after drinking during the day. Different sex stories of 4 couples.

The story of a man who observes couples and contemplates whether it would be good to get married.

Mi-yeon will do anything to change the mind of her boyfriend, Joon-ha. Then one day, Mi-yeon calls Joon-ha, her friend So-jin, and So-jin's boyfriend Do-joon to her house, and she begins to take off her clothes in front of them.

Unsatisfied with her relationship with her boyfriend, Ji-hee receives a business trip massage through the introduction of her older sister, Mi-yeon. After that, Ji-hee falls in love and becomes obsessed with giving massage services to her on business trips.

A brother and sister met at an orphanage and lived together for a long time. The brother came to meet her sister, who had already gotten married, to listen to her worries. A very drunk sister brings up the story of his husband cheating on him...

So-jin fell in love with the fun of contacting Do-joon, a man she met on a random chat that started by chance. Then one day, starting with a phone call, she crosses the line that she shouldn't cross.

A female college student is working part-time at her father's laundromat business. One day she had an unusual laundry request: to have the laundry delivered to the customer's house. She carefully opens the door and enters the house, where she witnesses sex between a man, who appears to be the owner, and a woman. The female college student, who hides in the kitchen, watches the scene and is caught by the man while masturbating. A man who is having fun offers sex to her, who is in a state of excitement, and the atmosphere between them becomes luscious.

Yeon was determined to expose the company’s external matters which were being kept hidden by the mysterious and transparent woman named Chae Yeon. In her pursuit for the truth, Yeon found herself serving time in prison. But this did not deter her from seeking revenge on Chae Yeon. She was willing to use any means necessary, disregarding the consequences, to get her retribution. Driven by her anger and determination, Yeon chose to embrace the same path as the transparent woman and become one herself. However, this decision would lead her down a dark and dangerous road filled with secrecy and risk. The suspenseful and thrilling journey of revenge starts to unfold, leaving Yeon with no choice but to move forward despite the challenges that lie ahead.