I thought the whole movie was.. Ambivalent towards the Japaneese.Then aside from the Japanese captain and one or two members showing up intermittently throughout the film, the Japanese crew that were rescued just sort of disappeared until the end.
...Where they served as mere manual labor to move a cannon shell down the hall...
From one side, it's in Peal Harbour, US and Japan soldiers are first competing and then fighting together on a single ship. On the other hand: The Japan crew seems expendable and unimportant, and the aliens (attacking Hawaii first, just like some other country before them..) seem to have a bit asian look if you ask me..
So either I am overinterpretating or the director did some double meaning stuff.