A Locked Room

Ma Mi Hwa is an instructor at a math academy, who always goes home at 8 p.m. to prepare meals for her son who is always stuck at his room. One day, a strange new student named Lee Ji Hoon comes to her class, and her daily life rapidly changes because of him. Through several incidents with Lee Ji Hoon, she eventually becomes able to face the past of her son being bullied.
(Source: Funnycon Distribution Vimeo)