Please help me name the movie....its old japaneese or korean movie.?

its very old..and its story is like :- theres this army aand they have a leader ofcourse, okay so the army dies but they dont realise they have died later their leader tells them that they have died and asks them go back to where they came from, so they march back to the dark tunnel in the end. its really sad, i even cried for them. please name it.