Woo Ji Soo (Kim Nu Ri), a 17-year-old high schooler, harbors a secret love for her best friend Ha Da Som's (Lee Jin Sol) boyfriend, Jo Ah Sung (Jung Su Bin). Despite her feelings, she continues to help the couple navigate their relationship, acting as a messenger during their frequent fights. After confiding in So Mi Ji (Kim Seo Yeon), a girl from another school, Ji Soo becomes anxious when So Mi Ji transfers to her school, fearing her secret might be exposed. When a misunderstanding leads her classmates to suspect a romantic connection between Ji Soo and Jo Ah Sung, rumors begin to spread, creating tension and potential drama. This is a 2019 South Korean drama series directed by Wang Hye Ryung.