Dae-sung and Jung-won have been married for two years. They are car pooling with the married couple next door. Woo-sung and Tae-hee don't interfere with each others' lives. However, these two couple don't just share cars, they share each others' wives too...

Dong-hoon moves to a new house. On the day of moving, he comes to the landlord to pick up the keys he didn't receive. He is happy to be seeing the beautiful Ji-hyeon. Ji-hyeon noticed Dong-hoon's interest. Dong-hoon had a housewarming celebration with his friend Min-soo. Ji-hyeon started to take a hold on the drunk Min-soo and then passed out in no time. The next day, Dong-hoon happily welcomes Ji-hyeon, who came to him without knowing what happened.