The secret story of the sexiest and youthful sisters that can not be revealed! The confidential secret of the boyfriends who reveal is revealed. He is a sister. Sukyoung is between Sangwoo and Jinhee and loving each other. The two of them talk about their lover, and when they accidentally find out that their boyfriends are high school alumni, they ask about her sister's boyfriend ...

Eun-joo is always horny and her hobby is to post pictures of herself online and seduce men. One day, her friend's boyfriend Sung-jin has no place to stay moves into their house. While they live together, Sung-jin realizes that Eun-joo is the woman he met online and makes a move on her everytime Young-joo is not there...

Jung-sik and Ji-young got married after a hot relationship, but it has cooled down. One day, Yoon-soo and Sun-young move in next door. They have been married for 5 years, but still look like they're madly in love. Ji-young talks to them about her problems and they decide to help her sex life.

Hwa Young takes out her best clothes and visits the lawyer's office nearby. Hwa Young is having a hard time because she is being stalked by a man who was once a lover. Tae Hyun, a lawyer with a playboy temperament, watches such Hwa Young with interest.

Ji-eun, a Korean female college student who came to Japan to study, works part-time at a convenience store to pay for tuition and living expenses. The friendly store owner invites Ji-eun and Min-woo to his house. Ji-eun and Min-woo are forced to suffer between their mistress and her lover. From that day on, the mistress torments Ji-eun by revealing her true nature. Min-woo, who is worse than her, drags Ji-eun out of the convenience store and falls in love with her again.

Sang-Woo's house, Byeongjin, the younger brother of the family, is about to live for a month. Wanjin pretends to see Sang-Woo's lover, Jinju. Sang-woo finds out that they are dating for a while, and Sang-woo is complicated. The difference is Sangwoo, asking Jinju about her relationship with Wanjin. Her younger brother, Wanjin, doesn't even know Sang-woo's situation, and even invites girlfriend Seol-young to Sang-woo's house. While Wanjin goes out, Sang-woo twists Seol-young with revenge on Wan-jin. It does not come in. While Sang-woo and Seol-young are getting deeper between them, Jin-ju is coming home to reconcile with Sang-woo. So, who will she choose between her girlfriend Jin-ju and her sister Seol-young?

Jang-hyeon is in the leasing business and he lives with his son Byeong-cheol. One day he gets a call from his daughter-in-law in the States that she's coming to Korea for a while and will be staying at Jang-hyeon's house. Jang-hyeon goes to pick her up from the airport and Byeong-cheol calls his girlfriend for some mature fun, but the daughter-in-law walks in.

Saryu runs a bar, and after her husband's death she ends up with his friend Tanaka, who was by her side to comfort her all along. Then one day, a Korean man named Min-gyu comes to the bar, and Saryu feels like she can open up to him, because he looks just like her late husband, Haruto. Min-gyu goes to her house one day and understands why she likes him after seeing Haruto's picture, and feels dear for her. Meanwhile, Tanaka, who is currently with Saryu, desires perverted things from Yui, who works at the bar... He tells her he killed his friend Haruto to have his wife. Yui takes revenge on Tanaka, as she thinks fondly of Saryu.

Dong-hoon is a detective who only has eyes for his foster daughter Yoon-ji. However, she's unemployed and only likes to party. One day, she brings her friend Hye-ri home. Hye-ri doesn't leave and acts as though she lives there, even bringing her boyfriend into the house for some adult playtime, tempting Dong-hoon.

The gentle gesture of the three sisters surrounding the male housekeeper begins. The three sisters are not the food of the housemaid but the housekeeper's body.