High school girls Lee Eun-bi and Ko Eun-byeol live miles apart and their experiences are vastly different, yet they share an uncanny resemblance.

After ten days of frantic searching, Eun-byeol's mom receives a call from the hospital, where she learns her daughter doesn't remember anything.

Yeong-eun's mom demands an investigation for the recent incident and alleged bullying, but the situation is complicated by Eun-byeol's amnesia.

Eun-bi's confusing life is further complicated by a new transfer student, who keeps wanting to hang out with her group of friends.

So-yeong schemes relentlessly against Eun-bi. Tae-gwang pretends not to be concerned despite being secretly worried about Eun-byeol.

Eun-bi resolves to be more like Eun-byeol and stands up to So-yeong. I-an offers to help, but Eun-bi can't get herself to tell him the truth.

Three teams in Eun-bi's class fail to turn in their group projects after someone tampers with their computers. Eun-bi suspects So-yeong.

I-an goes to see Eun-byeol's mom to ascertain what happened to Eun-byeol. During I-an's absence, Tae-gwang and Eun-bi grow closer to each other.

Feeling responsible for I-an's injury, Eun-bi tries to help him, but he pushes her away. So-yeong enlists her mom's help to get out of a tight spot.

Eun-byeol's mom sees her daughter confronting another student. Tae-gwang tries to help Eun-bi from being forced to transfer to another school.

While checking the school's security footage, Mr. Kim spots something shocking. Tae-gwang discusses Eun-byeol's situation with his father.

So-yeong threatens to reveal the results of the handwriting analysis in front of the class. Tae-gwang senses something very different about Eun-bi.

Eun-bi is caught between two places she considers home. I-an has mixed feelings for Eun-bi. Tae-gwang ponders what to do with the autopsy report.

I-an tells Tae-gwang the real reason why he was angry at Eun-bi. While trying to repair her phone, So-yeong remembers the video that she took before.

Eun-bi's family decides to move and start afresh. Eun-bi makes her feelings known to Tae-gwang and I-an, and Eun-byeol says her goodbyes.