Who Are You: School 2015 (2015)

Go Eun-byul and Lee Eun-bi are identical twins separated at birth. Eun-bi lives in an orphanage in Tongyeong, where she is quietly bullied by a gang of mean girls, while her sister Eun-byul is a popular student at a prestigious private high school in Gangnam. During a class field trip to Tongyeong, Eun-byul mysteriously vanishes. Around the same time, Eun-bi loses her memory after a near-death incident and is mistaken for Eun-byul. Stepping into her sister's shoes, Eun-bi must navigate high school life, hidden secrets, and a complicated love triangle while searching for her lost memories and the truth about her sister.