Night has fallen

Ahn Na Hee is a soft and timid girl who quickly becomes a pawn in others' manipulations, desperately seeking a strong patron.

Park Woo Ram (is a boy with an unrequited crush on one of his classmates. The psychological pressure quickly breaks him, pushing him to impulsive and fatal actions.

Heo Yul is a close friend of Kyung Joon. Initially, he obeys the gang leader unquestioningly, but fear for his life makes him doubt his loyalty to his friend.

Kim So Mi - Class Role: Class Vice President. A selfish, arrogant, and popular girl accustomed to being the center of attention.

Ko Kyung-joon - Role in class: The school's biggest bully, leader of the sports team, and a cruel manipulator. Accustomed to subjugating people by force.

Jin Da Bum - Role in class: The main victim of school bullying, a weak and downtrodden boy who constantly endures bullying from local bullies.

Oh Jung-won - Role in class: The school's top student and a math genius. She keeps to herself and is secretive, which is why she is considered an outcast, and her only close friend is Yoon-seo.

Kim Joon Hee - Role in class: Class president. A kind, responsible guy with a strong sense of justice, respected by his peers.

Lee Yoon Seo - Role in class: An attentive, quiet, and observant girl who enjoys reading detective stories. She suffers from asthma.

The Muryeong Youth Center is a secluded, rural recreation and training complex. In the context of the plot, it functions as an isolated "sanatorium-boarding house."
The center is designed as a typical Korean training camp for youth groups, including several functional areas:
Main Lobby and Recreation Area
A spacious, double-height room with high ceilings, where students in grades 2 and 3 initially gather. It features sofas and vending machines.

Sports / Assembly Hall
A huge room with high stands, basketball hoops and equipment.

Dining room and kitchen block
A large area with rows of tables and a serving line.

Architecture and external design
Total isolation: The center is located deep in the mountains and woods. The road to it leads through dense forest, and the only connection to civilization is the bus that leaves immediately after the students drop off.
Main Building: A modern multi-story building made of concrete, glass, and brick with strict geometric shapes. Panoramic windows provide plenty of light during normal hours, but at night they become black, reflective surfaces.

Basements and Boiler Room
Dark, labyrinthine technical corridors with pipes, ventilation and control panels.

Living rooms (hostel)
Separate bedrooms for boys and girls. The rooms are minimalist in style, with wooden floors, traditional futon mattresses, and lockers for personal belongings.

Lack of communication: Immediately after arriving in the building, mobile communication, internet and GPS signal are completely lost.