





A boy falls to his death at school, but Ok Chan-mi does not believe that her twin brother, Park Won-seok, committed suicide. Chan-mi transfers to her brother's school, Yongtan High, and meets Ji Soo-heon, who witnessed her brother's death. A "hero," who avenges bullied students, appears at Yongtan High. Chan-mi speculates that it may be connected to her brother and starts looking for this hero.
This is a dramatic thriller for mature audiences with fast-paced editing, intense scenes, and complex storytelling — completely inappropriate and overstimulating for infants and toddlers.
Stimulus rating reflects pacing, visual complexity, and sensory intensity — factors associated with attention development in children under 3. Learn more
Ratings based on MPAA/TV classification and TMDB metadata. Updated March 2026.
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