Apartment (S01E03)

After Seon-ah tumbles from the rooftop, she slips into a coma, leaving Ji-wook overwhelmed with guilt and fury. Determined to uncover the truth, he teams up with Hyun-heup to track down the person responsible. Simultaneously, Jung-woo, an English teacher at Bangju High School, discovers his fiancée's betrayal just days before their wedding and ends the engagement. Shortly thereafter, he notices a mysterious pair of glasses resting on his desk...