Booze, smokes, and boys—Hayoon’s life was a checklist of bad decisions. At 20, repeating a year in school, she thought she’d seen it all… until her new homeroom teacher, Mr. Hyungwon, walked in.

Unfazed by the rumors swirling around her, Hyungwon is calm, mysterious, and always full of surprises. Naturally, Hayoon’s curiosity turns into something deeper—her first taste of real love.

“I love you, Teacher.”

“That’s not love. You’re just confused. It happens at your age.”

But unlike the guys who usually fall for her with a wink and a smile, Hyungwon is the ultimate fortress—cold, distant, and impossible to crack.

Still, Hayoon’s not backing down. That wall of his? She’s ready to tear it down, brick by brick.