Once Upon a Time in High School

Yoo Ha (Hangul: 유하; or spelled Yu Ha; born February 9, 1963) is a South Korean film director, screenwriter and a contemporary poet. He directed the commercially successful and critically acclaimed film A Dirty Carnival. It’s a gangster movie which some allusions to Martin Scorsese films like Gangs of New York, Mean Streets and Goodfellas. —Wikipedia