This film is weird. Director Oshima had worked for Jean-Luc Goddard, and is clearly paying homage to the wacky French director here.
"Three Drunkards Come Home", as this film is sometimes called, begins with a surreal situation of three students playing on the beach and having their clothes pinched by Korean (refugees? soldiers?). They are then mistaken for Koreans and begin to play the roles themselves. Then the story starts again at the halfway point, continues for at least five minutes the same way, and gradually diverges.
You need to be a serious film fan to take this sort of stuff. If you aren't a fan of Oshima or Goddard, don't go anywhere near this film. If you are, then you have some idea of what to expect.
As a fan of Oshima but not of Goddard, I sat through this film with mixed feelings. As in Death By Hanging, Oshima makes some strong points about the Japanese discrimination against Koreans. But as its apparently main purpose and theme, I feel this was handled much better in Death By Hanging, and I consider Three Drunkards Come Home to be one of his weaker efforts.