Byul and Yong got married when they were 17, with their parents' permission, to adopt a baby. They were happy together but duo to immaturity ended up divorced after 5 years and remained friends.

10 years later, they are still close and their partners are jealous, especially because Yong's parents adore Byul.

The former couple go to a school reunion, drink too much and things escalate.

After that, sparkles may wake sleeping feelings.