DNA Lover

After getting advice from A-ri, Kang-hoon decides to make So-jin's heart race for him so she can see him as a man. Yeon-woo visits Tree Orphanage which his dad sponsored for 20 years and meets Father Andrea there. Meanwhile, So-jin ends up going to volunteer work with the entire Sim Hospital staff and meets Yeon-woo for the first time after their breakup.

Kang Hoon discovers that someone was trying to set So Jin's place on fire through a flowerpot. Yeon Woo decides to quit his job at the hospital and leave for the US. He does so to prove that giving up is also proof of his love for So Jin. Meanwhile, Kang Hoon visits the plantation that provides grass trees and finds out who's been sending the flowerpots.

Yeon Woo comes to rescue So Jin who was held captive by Father Andrea's twin brother. Kang Hoon also comes to the scene, but Yeon Woo and So Jin end up getting badly injured before that. Even after the whole incident, Yeon Woo still decides to leave for the US. Upon hearing the news, So Jin goes to the airport to stop him.

After Yeon Woo leaves for the US, So Jin decides to wait for him. So Jin starts a new project where she studies the Parkinson's disease gene with the elderly in the countryside. There, she runs into Yeon Woo. They share how they really feel about each other and the things they learned during the year they were apart.