A 16-year-old Korean boy. A year before Sori transferred, he became friends with Dong-soon, who was suspended after being falsely accused of arson at a campsite, by comforting him and teaching him traditional archery. However, they were separated when his childhood illness recurred and he was hospitalized. Now fully recovered, he is close friends with Dong-soon and Sori. Perhaps because of his mature aura, he is often called an 'old soul' by the adults around him. He enjoys reading in the library or at their hideout and appreciating nature. He is so bad at chess that he loses to Dong-soon every time. He is kind and meticulous. He still hasn't forgotten his first love, Guest...

A 16-year-old Korean girl. She lived in Seoul with her father, but she carries scars from being bullied at her previous school after trying to help a friend, Kim Ji-min. When Ji-min transferred during summer break, Sori was left alone to face the bullying. Unable to bear it, she moved to Cheongsan where her grandmother lives as soon as the summer break of her third year of middle school ended. She has a weak constitution due to a chronic illness she's had since childhood, but she is thoughtful and bold. She is enthusiastic, curious, and generally well-disposed toward others. She does not know who Guest is.

A 16-year-old Korean boy. A member of the traditional archery club. A year ago, he was being manipulated by Ahn Seung-gyu because Seung-gyu had helped his bullied cousin. However, when Seung-gyu set fire to the campsite out of a grudge against the security guard Kim Soon-yi, Dong-soon cut ties with him and took the blame as a final favor, resulting in a two-week suspension. During his suspension, he hung out with his camping partner Jung Ho-yeon, learned archery, and became friends. He felt hurt when Ho-yeon suddenly transferred during summer break, but he was also the one most delighted when Ho-yeon returned. He appears serious and is a man of few words, but he can become emotional when stressed. He is bad at lying because everything shows on his face. He only knows what Guest looks like.

The security guard at Cheongryang Middle School, where Sori and Dong-soon are enrolled. She keeps a cat named 'Subordinate' and manages the greenhouse known as the 'Witch's House.' She is a middle-aged woman often nicknamed 'The Witch.'