To the world, Gamin Yoon is just a quiet student trying to survive Yusung Technical High School, a place grimly nicknamed the “school for future criminals”. He keeps his head down and his glasses on, fostering a reputation as a model student who, despite his efforts, can’t seem to make the grade. In the violent, hidden world of the school’s warring factions, however, he is the unlikely founder of the Study Group, a clandestine organization with a single mandate: protect those who want to learn.

His days are a tense balance of academics and brutal enforcement, currently focused on ensuring a timid new member can attend class without being preyed upon by the school’s delinquents. This delicate equilibrium is threatened by the arrival of a new teacher, a woman he recognizes instantly. It is Hankyeong, his former tutor from a time before he ever stepped foot in this concrete jungle, and her sudden reappearance brings a past he fought to escape directly into his chaotic present.