A-na, an easygoing, eccentric student finds her new math teacher Ms. Yu absolutely alluring; it is love at first sight. She is determined to make her new teacher see her in a different light; to be hers. As she traverses her newfound feelings, she must first prove to herself that she has the worth to feel her teacher's love. Yuha, a recent college graduate, takes a job at Heart High. In her first year on the job, she must learn the ropes of the career including teaching responsibilities, mingling with co-workers, and handling a variety of kids, most notably the loud obnoxiously talkative basketball player A-na. Yet, for some odd reason, she keeps seeming to meet her by chance.

Carmen is innocent and careful. Jiwoo is bold and dangerous. They were never meant to fall for each other but they do...

A Na has never followed the rules-and she never plans to. Bold, reckless, and effortlessly charming, she lives her life pushing limits and getting under people's skin just for fun. Yuha is the complete opposite. As one of the most disciplined students in school, she believes rules exist for a reason. Her world is built on structure, control, and focus-leaving no space for distractions, especially something as pointless as love. But everything starts to shift when A Na takes an interest in her. What begins as harmless teasing turns into something more persistent. A Na challenges Yuha at every turn, breaking rules just to see her reaction, stepping closer just to watch her lose composure. Yuha refuses to be affected. She won't bend, won't break, and definitely won't fall for someone like A Na. ...Right? Because the more A Na chases, the harder it becomes for Yuha to ignore the feeling she's been avoiding all along. A story of tension, defiance, and a heart that might not be as untouchable as it seems.