Lin Ze and Chen Meng are all police cadets,but they are different kinds of people ——Lin Ze has high IQ and excellent academic performance, and he has excellent profile and crime scene restoration ability so that he has been practicing in Binjiang Police Force since his junior year. But Chen Meng is a common ignorant girl. She not only sets up a private arena in the school but also sells all kinds of "contraband". It seems that she doesn't have anything outstanding except for having a good martial arts skill. However ,in their senior year, the quota of Binjiang Police Force and the quota of staying in the school are all for Chen Meng. Since then Lin Ze and Chen Meng start their tangled relationship.