Soo Ji's mother and Si Hyun's father make an official announcement about their engagement. Only then, do Soo Ji, Si Hyun, and Se Joo find out about the adults' relationship. Ki Young, Soo Ji's first love, makes snide remarks about the surprise announcement, and Se Joo stands up for her. Meanwhile, the three musketeers try to find a way to stop their parents from getting married.