My Dictator 2014 on netflix

Sung-geun is an untalented actor who makes a living playing minor roles. He happens to land on the role as Kim Il-sung, the former leader of North Korea, for the rehearsal of the South-North Korea Summit. Sung-geun becomes passionately immersed in his role, motivated by his son who looks up to him. However, the summit is not realized, and Sung-geun ends up lost in the delusion that he really is Kim Il-sung.