A high school student who conquered the school with her fists is back, this time in a tracksuit! 'Min Ah', equipped with a strong sense of justice and great resilience, lost her parents in an accident as a child and grew up with her aunt. She's a girl with a slightly excessive sense of justice. Min Ah, who entered high school with a promise to 'never fight again,' dreams of an ordinary new start, but from day one, she's drawn to 'Min Ki,' her handsome classmate who seems to have a sense of justice. The problem is 'Se Hyuk,' the leader of a bully circle targeting Min Ki. Seeing Se Hyuk's gang harassing Min Ki, Min Ah can't help but rescue Min Ki in a 'face-covering tracksuit.' From that day on, the school buzzes with efforts to find the identity of the tracksuit guy, and Min Ki begins a serious investigation (?) to find his savior. Meanwhile, a love triangle between Min Ah, Hye Ri, and Se Hyuk over Min Ki ignites, and Min Ah leads a triple life: pretending to be normal + pretending to be a delinquent + pretending to be in love, all while hiding her identity. But for Min Ah, whose sense of justice explodes and who has a hot temper, is that even possible? Love gets tangled, her identity is at risk of being exposed, and the fights escalate...