The Mysterious Class Season 1 Episode 6
꼭꼭 숨어라 귀신 정체 들킬라 (Hide Well, The Ghost's Identity Will Be Discovered)
Jeong-woo is hospitalized after the school-wide paranormal event at the spring festival. Class 4 finds itself pointing fingers at each other. Do-young discovers the ghost's identity and Haruto is forced to explain himself.