FirstLoveMovies

Go Eun-byul and Lee Eun-bi (both played by Kim So-hyun) are identical twins, separated after one is adopted at the age of 5. Eun-bi lives at the Love House, an orphanage in Tongyeong, South Gyeongsang Province, where the younger residents look up to her as a mother figure. However, she hides the fact that she is bullied at school by a gang of mean girls led by Kang So-young, while teachers turn a blind eye.

On the other hand, Go Eun-byul is studying at Sekang High School, the most prestigious private high school in Seoul's Gangnam District. Eun-byul's best friend is Han Yi-an (Nam Joo-hyuk), the school's star swimmer and is in love with her since childhood.

However, only Eun-byul is aware of the other's existence. Unlike the cheerful Eun-bi, Eun-byul is prickly and secretive.

One day, on a school field trip to Tongyeong, Eun-byul mysteriously disappears. At the same time, Eun-bi is unjustly expelled from her school and jumps off a bridge in a suicide attempt. Ten days later, the injured and amnesiac Eun-bi is mistaken for her twin, Eun-byul, and her adoptive mother takes her home to Seoul, where she starts living as Eun-byul. However, her memory soon returns.

Eun-bi faces many challenges as Kang So-young transfers to Sekang High School and tries to reveal her real identity, as well as using her Dad's authority to make Eun-bi transfer from the school. Luckily, Gong Tae-kwang (Yook Sung-jae), Eun-bi's classmate and the school troublemaker, protects her whenever So-young tries to bully her. Eun-bi also stands up to So-young and disproves her claims about her identity, as well as ruining her plans to have her transferred. Eun-bi tells Tae-kwang her real identity, and he eventually begins to develop feelings for her.

Soon, the real Eun-byul is shown to be alive and was in hiding all this time in order to give happiness and love to her sister who never had it. The two meet each other and make up and reveal to everyone their real identities. Everyone is confused at first but come around and Eun-Byul friends decide to accept Eun-bi as their best friend too after spending times together. Han Yi-An is annoyed but he comes around as he has already fallen for Eun-bi. Eun-byul decides to enrol at a different college of her dreams and she departs whilst staying on good terms with everyone and Eun-bi stays at Sekang High School and is enjoying her new life. Even though she has feelings for both Tae-kwang and Yi-an she remains good friends with both of them in the end.