What Sugiyama and his fellow revisionists (or, to use a more correct term, negationists) are doing is something different. They think the scale of Japanese atrocities is simply a concoction of the West, that the years of testimony and research supporting the use of "comfort women" (something acknowledged by the Japanese government itself in 1993) is actually a collection of "fallacies, distortions, biases and factual errors". Some of his colleagues in negationist movements like the "Committee for Historical Facts" even believe the Rape of Nanking simply didn't take place.
These men, all of them politically conservative and many of them of an age to remember the war, can be found lightly scattered amongst Japanese politics. Shinzo Abe, for example, Prime Minister of Japan in 2006-07, held similar views. They are deeply committed to their beliefs, to the extent that on June 14, 2007, they took out a full-page advertisement in the Washington Post, in which they argued that the use of comfort women was "anything but the truth".
(This report even states Sugiyama initiated the whole thing).