Gi Dong and Yeong Joon run into each other in Gyeongju accidentally ten years after that night. The head of the school gang has become a passionate teacher of physical education and the shy nerd has become an elite gangster. The two shake their hands together but the memory of that night reminds them of the time they have gone through.Later, both fall in love with Joo Ran, the sister of Gi Dong's troublesome student Joo Seop at the same time. Her brother, Joo Seop wants to be a gangster like Yeong Joon. Who will get the heart of Joo Ran?