Purpose of Sex: Director's Cut

Ji-ho regrets marriage with her selfish, withholding husband. She is desperate for a real relationship and by chance falls for a man who is exhausted from his constant lonely state. It turns out that the man is her husband's colleague, but she continues to enjoy herself anyway. Her husband returns home from a business trip and witnesses something he didn't expect to see.

In dreams, a promised couple meet and fulfill their promise of a perfect wedding night.

Sung-chan and Soo-jin used to date. Soo-jin was expecting quality time together until he comes home drunk. A few years later, they break up and Soo-jin appears in front of Sung-chan who is about to marry Yoo-ri. Sung-chan and Soo-jin still like each other and they both desire each other. Will Sung-chan be happily married?

Yong-pal has an unsatisfactory night with his girlfriend Amy and he goes to a sex therapist called Ban-hee to recover things in his relationship. Through the intimate 'therapy' he gets with Ban-hee, Yong-pal is confident that he's better and goes to see Amy. They have a hot time and they are content with each other but Yong-pal heads to see Ban-hee once again...

Hyeon-seok dreams of becoming a famous director. His wife leaves to Japan to get funds for her husband's movie and asks him to audition a new actress. On the day of the audition, Hyeok-seok asks Eun-bi about her values and passion in movies and when she says she'll do anything and even strip, Hyeon-seok tells her to pretend he's a friend. He tells her to seduce him. Eun-bi does everythng she can to do so...

A man makes erotic films and it complicates his relationship with his girlfriend so he begins to look elsewhere for love.

A part-time worker is fascinated by a customer. When she's fired and upset, she takes on a new partner for comfort.

Yoo-kyung and Min-young are best friends and rivals. Min-young has a boyfriend and is too busy to hang out with Yoo-kyung. Lonely, Yoo-kyung comforts herself with a banana that surprises her when a handsome man pops out of it. Yoo-kyung has a fun time hanging out with the man who is cursed and trapped in the banana. Meanwhile, Min-young's boyfriend confesses to Yoo-kyung that he actually has had a crush on her. However, Min-young finds out what happened and steals the 'special banana'...

Jin-woo lives in his friend's house and he likes his friend's sister. Although he has a girlfriend, he's constantly looking for a chance to approach the sister. However, he doesn't get the nerve to do so until he approaches her with the excuse that wearing a woman's panties on an important day brings luck.

Mi-ni and Chul-soo live together. They grow comfortable and familiar with each other until they start to yearn for something more. They go to the mountains for some fresh air and something new to do. However, Chul-soo feels attracted to the cabin owner Yoo-rin and starts to peek into her private life...

Sun-gyu was looking for a house when ends up living in Ji-won's house. One day, Ji-won is having phone sex with her boyfriend in the living room and Sun-gyu dreams of having sex with her. In the end, he gets a call girl to fullfill his needs but it's not enough. Meanwhile, Ji-won is looking for her missing underwear when Sun-gyu comes home and she approaches him...

Ji-min wants to explore new risky venues of pleasure with her boyfriend. Voyeurism becomes a new fantasy that may turn into reality.

Pan-joon spots Choon-hyang who is walking alone on a deserted countryside road and approaches her with naughty things in mind. However, she's strange. She doesn't answer his questions properly. However, Pan-joon doesn't give up and asks her to go with him.

Min-chul misses his mother who left 5 years ago. His father Jung-soo brings Hyun-ah, a new mother who looks just like his mother. He recalls his mother as he watches Hyun-ah endure the violence his father shows, but he starts to see her as a woman.

Song-yi and Jae-suk are young lovers, but She is tired of her daily life with him. They try to make it work, but they end up breaking up. Meanwhile, Seung-min neglects his wife. One day, he's scolded by his superior and heads towards the river. He meets Song-yi there and they go back home to spend an erotic time together taking naked photos. Meanwhile, Byul is neglected by her husband and she is lonely. She meets a man online and has a great time.