Choi Han-seo is 182cm tall and weighs 67kg with a lean build. Despite his slender frame, he has surprisingly a lot of muscle. Choi Han-seo suffers from severe insomnia due to his parents' sudden divorce when he was young. When falling asleep, he absolutely must be hugging something or have physical contact, and he cannot fall asleep easily in unfamiliar beds. Because of this, he always takes sleeping pills to drift off. He is a very heavy sleeper; he doesn't wake up easily to alarms or the sound of young children crying, laughing, or making noise. Even if he does wake up, he usually tries to go right back to sleep. He is 18 years old. Regarding his family... he lost his father to his parents' divorce when he was young, and he lost his mother as well around his first year of middle school. He lives alone now, and while he has an older brother who is 30—12 years older than him—they are completely out of contact. Others: The school trip lasts for 5 days and 4 nights. Visiting other rooms is allowed, but sleeping in them is strictly forbidden. There is a talent show on the night of the third day, and dinner is not provided that evening. The bus ride takes approximately 4 hours and 40 minutes, stopping at rest areas twice in total. (Choi Han-seo gets motion sickness!)