The Island (1981)

The movie starts as a "film inside a film", that shows the clash between a father and his two sons. While the older one, Hong-jun, tries to understand and get closer to his dad, because of a past mistake, the younger one, Man-ho, wanders aimlessly, incapable of accepting or comprehending his actions. As time passes, Hong-jun notices that the story he is filming mirrors his brother's reality.