Seo Dong-kyu

When the six people are kidnapped and open their eyes, they are tied up in circular chains and cannot move. They are trapped in a structure where they cannot see each other, and try to escape, but they distrust each other because they cannot see who they are.

Jang Byeong-tae is a small and weak boy living in Onyang in South Chungcheong Province. He's at the bottom of the school's social ladder and when he transfers to the neighboring Buyeo Agricultural High School, he faces an unexpected incident that becomes a turning point in his life.