The series is partly inspired by a horrifying in Cheongju, South Korea. A middle school girl was extorted and physically tortured by her classmates for a month, including being burned with a hair straightener—a detail depicted vividly in the show's early flashbacks to illustrate the severity of the trauma fueling Dong-eun’s rage.
As an adult, Dong-eun meticulously gathers information on her former bullies. She discovers their current status: ringleader Park Yeon-jin is a successful weathercaster married into wealth; Jeon Jae-joon manages a high-end boutique; and others have become drug addicts or social climbers. The series is partly inspired by a horrifying
Dong-eun moves into an apartment in Semyeong that directly overlooks Yeon-jin’s house, literally positioning herself to watch over her enemy's life. The Real-Life Inspiration Jeon Jae-joon manages a high-end boutique