Thirty, but Seventeen

Performing at the Festival (1x20)

Air date: Aug 28, 2018

While working, Woo Jin notices that a worker is trying to introduce his son to Seo Ri. It keeps bothering him, and he tries his best to end their conversation. Meanwhile, Seo Ri decides to take courage and perform at the festival alongside Professor Shim Myung Hwan, and Tae Rin is not happy upon hearing the news.