A Wacky Switch(2004)

Original title: 나두야 간다

Dong-Hwa is a complete loser, whose first novel called 'I met Kafka' brought the publishing company bankruptcy. To bring home the bacon, he tries to drive a taxi but only ends up running over someone. One day Dong-Hwa is offered a job to do ghostwriting for a CEO named Man-Chul, who turns out to be the ringleader of the biggest criminal syndicate in Korea. Dong-Hwa soon finds himself perfectly at ease in the mob, while Man-Chul starts learning about the other part of the world.