Hyunjin is recovering from a car accident which left her with impaired speech. Being able to only communicate through writing and animal noises, her parents become increasingly more frustrated as therapy doesn't seem to be helping. She missed the largest part of the new school year at the new school since her parents moved a few months ago after which the accident occurred sadly. She's forced to go to school during winter break with slow students, getting tutored. She's nervous people will judge her.

Heejin is a model student who loves to help whenever she can. She's very popular in school and known to be friendly to all. Like every year so far, she's signed up to help tutor some kids during winter break. As a senior, everyone wanted to befriend her and claim her as a tutor. She gets assigned to Hyunjin, the senior who's seat has been empty since the start of the year.