The Substitute

The plot revolves around a model student from a prestigious private high school, who is forced to take the CSAT (College Scholastic Ability Test) instead of another student after being blackmailed. This starting point paves the way for a veritable game of manipulation, where betrayal, guilt and lies intersect in a world where grades define an individual's worth.

Bae Hyeon-seong plays Nam Jae-yeop, a seemingly perfect student whose inner flaws gradually begin to reveal themselves. Cha Kang-yoon plays Kang Geon-tae, a brilliant student from a modest background with a school scholarship, who hides a heavy secret from his past. As for Park Yoon-ho, he plays Joo Hee-dong, Kang Geon-tae's only friend, a character who will upset the course of the story with unexpected twists and turns.

The whole question is how a one-day deal—sealed by their mutual silence—will transform their relationship. Each harbors their own desires, and their choices, in an extreme situation, promise betrayals and plot twists. The first teaser already hinted at a shift in the balance of power.

In terms of production, the series sets itself apart from classic school dramas by adding suspense to a subject familiar to all Koreans. Three young men, each with his own flaws and desires, each holding the others hostage through their weaknesses: enough to turn a simple exam into a dangerous game.