Soul Calibur 2 wasn't only released on the GameCube in Japan, but also on the Playstation 2 and Xbox on the same day; March 27th.

It sold a total of 91,000 copies on its first day (very impressive!). These are the statistics for each individual console:

PlayStation 2 - 42,648

GameCube - 32,948

Xbox - 15,503

Nintendo's console did pretty well if you consider the fact that the Playstation 2 is more popular in Japan than the GameCube. The Xbox, third in the Japanese console war, also sold a considerable amount of copies.