Lee Hae Soo

Lee Hae-soo can't leave the school grounds because the sacred willow tree in the backyard restricts his movement beyond its reach. So the ghost chose a slovenly girl to become his "key to freedom" by killing her three tormentors. The monster within him thirsted for revenge, thirsted for blood, but Hae-soo sometimes pulled himself away from these obsessive thoughts. But Hae Soo still received the "key" to freedom, but not for full mobility. His contract with the girl and their bond had strengthened, so now he could go beyond the school grounds, but only to the place where Joo Eun Ha was. And so he was already in full swing at her house, while the naive girl didn't even suspect that her ghost "friend" could leave the school building at all. Hae Soo was definitely cruel and angry, quite selfish and cold, but still sometimes he acted a little softer.

The plot hinges on the tension between a sincere desire for support and a growing threat: what seems like salvation could turn into a curse. It combines psychological tension and supernatural elements, exploring the consequences of a person's connection with a ghost on the life of a young woman and those around her. The story's final arc leaves one uncertain as to whether Haesu truly is a friend or a source of trouble.

A ghost boy from school. He suddenly appears before Eun-ha and declares, "Let me be your friend now." Hae-soo becomes her protector from real-life bullies, but this connection draws a series of frightening and inexplicable events into her life. As the story unfolds, his true motives remain in question, blurring the line between sincere support and a dangerous curse.