Kim Jin-woo is just trying to get through his studies at the local cram school, but his focus is constantly shattered by the stunning, married math teacher. One day, he makes a scandalous observation: she doesn't wear underwear beneath her teaching attire. This shocking realization fuels an intense, hidden desire.

Drawn in by her seemingly emotionless, yet subtly provocative teaching style, Jin-woo finds himself obsessed. However, the emotional temperature of the academy heats up further when Jung Soo-ah, an unmarried female teacher who is equally captivating, starts playfully approaching him.

Caught between two beautiful instructors, Jin-woo navigates a dangerous triangle of forbidden desire and academic tension. The air in the cram school is thick, not just with exam pressure, but with lust and secrecy. The unspoken rules of the classroom are about to be shattered by the intense desires flowing between these three.

/ Alternatives: 노브라의 학원 선생님