San-ha and Hae-jun come back on Ju-won's birthday after ten years. Though they haven't seen each other for years, unlike what Ju-won had imagined, she feels indifferent about their return and is not happy to see them. Meanwhile, the family finds out a shocking truth about Hae-jun at Ju-won's birthday celebration.

San-ha's sudden confession startles Ju-won. While she tries to deny any romance between them and stay as siblings, she is overcome with mixed feelings. Hae-jun jokingly suggests getting married to Ju-won, upsetting San-ha. Meanwhile, a surprise visit from Seo-hyun shocks Jung-jae as an unexpected turn of events takes place.

San-ha and Ju-won finally confirm their feelings for one another. However, they soon become worried about how to break the news to their family and friends. Meanwhile, Hae-jun tries to pay back Jung-jae for everything he has done for him, but some misunderstandings develop as Hae-jun's source of money is revealed.