Dark hagwon classroom, children in early education are solving exam questions. The movie begins with the sound of teacher Eun-jeong's bell that the exam is over. Su-jin (Kim Min-seo), who was born into a wealthy family but tried to self-harm due to the stress of her early education, is caught by her teacher Eun-jeong (Choi Hye-yeon). But as cold as her fear, Eun-jung kindly teaches Soo-jin how to commit suicide. A few days later, the news comes to Eun-jung that Su-jin attempted to commit suicide and was taken to her emergency room, and Su-jin's mother visits her and becomes angry. Eun-jung treats Su-jin's mother as if nothing happened, and she is summoned by her academy head teacher (Yoo Hyo-jong) who finds it.