While North American gamers have been enjoying New Super Mario Bros. Wii since mid-November, the Japanese market didn't get its first taste of the platforming joy until last week. However, a report from Famitsu shows that the game's sales didn't suffer one little bit by the extra time, and in fact, New Super Mario Bros. Wii had the best first week of any Wii game ever released in Japan. Since the Japanese release of the game on December 3rd, 936,734 units have been sold. This surpasses the numbers of the previous first weeks of Super Smash Bros Brawl (816,198), Mario Kart Wii (608,147) and Monster Hunter 3 (582,548). A report from Andriasang put the game's day one sales at over 422,000 copies.

So we once again have definitive proof that just about everything Nintendo touches turns instantly to gold, and that the staying power of the Wii, seemingly in every market around the world, is as strong today as it has ever been. While no one can act surprised that New Super Mario Bros. Wii is doing well in Japan, I wonder if any analysts predicted a record breaking opening week for the game. Once again Nintendo has proven that, "hardcore" appeal or not, there is an audience for its games that few other publishers or developers can approach.

[Source]