I've never seen any of the movies you mentioned, so maybe these aren't at all what you're looking for.
The only things I can think of at the moment that are based on true stories:
Cart is based on events that really happened but is of course fictionalized
Set Me Free is based loosely on director/writer Kim Tae Yong's experiences (which is pretty crazy to think about! I loved this movie though)
Manshin is actually more like a documentary, dramatizing the life of a female shaman