The Foster Kid (Purinz)

After a particularly terrible experience with her adoptive father and a few drinks, Min Chaewon finds her much-needed escape from reality in her soon-to-be biology teacher. When the two meet again at the beginning of the school year, neither know what to make of the situation. But their conflict with each other is no match for the conflict Chaewon faces with her adoptive father, and the two soon find themselves developing a relationship that tests both of their willingness to let others in.
For entirely different reasons, they find themselves pushing each other away.
Until they realize that their reasons aren't so different at all.

Original story by @rosetothetop