My Boss, My Hero

Gye Do-shik (Jung Jun-ho) runs a gang in Seoul but keeps botching the plain daily work of the job, and nobody above him can work out why. His superiors send him back to finish high school, where he passes himself off as a 19-year-old and finds a school as corrupt and vicious as his own world. JK Youn sets the gangster among the schoolchildren, and the question is who in either building has any right to give orders.