I know this drama is amazing and Lee Sang Yoon was amazing as Cha hyeon seok but  the younger version of Cha hyeon seok played by Kim Hee Chan stole the entire drama for me, I mean his charisma and prescence were off the charts.

Yes, he was adorbale and like how he kept chasing the little girl.... He made me cry a few times too at the end... He was great in Guardian too