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.

Whenever she sees a messy kitchen, she calls her childhood friend Min-soo. Min-soo, complains in words but still brings side dishes to Seo-yeon. They're friends, but sex partners. Seo-yeon's relationship with Min-soo from their young age is natural. Min-soo is worried about Seo-yeon. He is jealous of the relationship between his younger friend Yeong-cheol and Seo-yeon.

Seo-yeon is running a boarding house. She has a habit of changing men every quarter. Yeong-cheol, who was recently brought to the house is cute, but he tends to be clingy in relationships which makes her feel a little uncomfortable. When Yeong-cheol is away from home, he calls Min-soo to his house. Min-soo provokes Yeong-cheol when he knows how Seo-yeon feels. But Seo-yeon's mind is different... Who will win Seo-yeon's heart?

Three people clean up the house for Min-soo who is new to the house. Yeong-cheol, who has become close friends while living in one house, is obsessed with Seo-yeon because he does not like Min-soo. Seo-yeon knows the relationship between the two and has a strange confidence watching the fight between the two. The fierce fight between the two men trying to win the relationship with Seo-yeon before Min-soo enters the house! The story of the unknown end is just beginning.

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.