Lee Hae-Jun (Kwak Dong-Yeon) transfers to a new middle school in an affluent area of Seoul. At his previous school, Lee Hae-Jun was the top ranked student in his grade. While going to his first day of class at his new school, he sees a girl leaning over a bridge. Thinking she may jump, he pulls her to the ground which she does not appreciate. Later that day, Lae Hae-Jun learns the girl he saw earlier is Jo Eun-Seo (Lee Yul-Eum). She's currently the top ranked student at his new school.

3 months later, with new test scores released, Lee Hae-Jun takes the top spot and bumps Jo Eun-Seo down to #2. Meanwhile, Jo Eun-Seo vows that Lee Hae-Jun won't beat her again. She recruits her classmate Jeong Na-Yeon (Lee Han-Na) to help her retake the top spot. Lee Hae-Jun finds himself falling for Jo Eun-Seo.