The japanese launched a d da type assault under fire at night, which they didn't even do at normandy. And by morning have landed 13 to 14 thousand guys and have established a beach head. Infiltration is essentially what can happen on a battlefield when you get surrounded by the enemy. Most of those troops could live with the results if they were caught behind enemy lines.
Japan's rising sun goes supernova and engulfs a huge area of Asia and the Pacific. A war without mercy begins to develop infusing the whole conflict with a savage vibe.