Woo Ji Soo (Kim Nu Ri) is a 17-year-old high schooler with a close friend – Ha Da Som (Lee Jin Sol) – and a very big secret. She is, unbeknownst to all of her classmates, in love with Ha Da Som’s boyfriend Jo Ah Sung (Jung Su Bin). Woo Ji Soo has decided to keep this from everyone at school, even though she finds it devastating to act as a go-between her female friend and Jo Ah Sung every time they fight. He constantly asks her for help with his relationship, while Ha Da Som frequently asks her to pass messages to him on her behalf. One day, hopeful that telling someone else her secret will help, she opens up to So Mi Ji (Kim Seo Yeon), a girl of the same age who attends another school. But when So Mi Ji suddenly transfers to Woo Ji Soo’s school, the latter worries that her guilty secret could be exposed for all to see. And when a misunderstanding drives the whole class to suspect that there is something going on between Woo Ji Soo and Jo Ah Sung, rumors start to spread – and tensions begin to rise! “The Guilty Secret” is a 2019 South Korean drama series that was directed by Wang Hye Ryung.