Lee Sori, a courteous and principled girl, attends a middle school riddled with harassment. Angered by the devastating impact it has had on her friend Kim Julie, she resolves to confront the tormentors. Unfortunately, this prompts the bullies to shift their focus onto Sori.
Thinking a fresh setting would free her from despair, Sori moves back to the city she once called home and enrolls in a new school. Yet, the haunting memories of past trauma push her to withdraw from everyone.
Just as Sori"s bleak reality starts to sink in, she finds a strange note stuck beneath her desk. The letter"s content piques her curiosity but only points to another message. Now chasing a seemingly endless chain of clues, Sori embarks on a hunt to uncover the real intent behind these letters and identify the nameless sender.
