Hye-rin Seo

The film is set in South Korea, 1962. Kang Soo-ha, a 21 year-old teacher from Seoul, takes his first job at a village school in Gangwon Province. One of his older students, 17 year-old Yun Hong-yeon, develops a crush on him, though her efforts to catch his attention seem to go unnoticed. Meanwhile, Soo-ha has fallen for Yang Eun-hee, another teacher at their school, and when Hong-yeon realises she does everything she can to discredit her older rival. (Wikepedia)

When a boy falls to his death at school his twin sister, Ok Chan Mi, does not believe that it is suicide. She transfers to Yongtan High, the school in question and meets a witness to her brother's death. When a bully-hunter also shows up at the school, Chan Mi suspects that it may be connected to her brother's death, and looks for this potential ally. (disney+)