Joon-seo and Eun-seo gradually develop feelings for each other that are more than brother and sister. Joon-seo tells Yumi that he is leaving her, but Yumi declares that she will never give up on him. Eun-soo is asked by Yumi to befriend Joon-seo, and she decides to hide her feelings for Joon-seo and go out with Tae-seok.