Wife Sharing.

Na-kyeong and Jeong-bin got married and soon after, falls in love with Hoon-i whom she met by chance and lives two houses away without her husband's konwledge. One day, Min-ju who she is close with, accidentally finds out so Na-kyeong introduces Hoon-i to Min-joo to try and cover up the secret. And Na-kyeong's husband, Jeong-bin, who met Min-joo told Min-joo a shocking truth...