Overall I'll be hugely surprised if Japan's kamikaze attack overcomes South Africa's laager defence. In terms of the historical timeline, I feel we're post-1942; Japan's element of surprise is properly gone, they're starting to fatigue due to limited (playing) resources, and the South African Rugby Corps is primed to kick down the door and storm the beaches of Iwo Jima/Okinawa.
EDIT: Though I wonder if the Bok's might change it up, not relentlessly kick quite so much and, instead, hold the ball for protracted periods early in that match just to A) allow themselves to hurl big, angry, vengeful humans at the Japanese; and B) make sure the Japanese can't run at them, build up momentum, and start getting tricky.