Will the USA Idol 3 work in Japan?

I will be traveling in Japan and wondering if the 3G bands of the USA version of the Idol 3 (6045I) are compatible with Japanese networks. From what I've read the best possibility is the 2100 MHz band, but just because the idol 3 specs say "2100 MHz" does that mean it includes (or at least overlaps) the Japanese 2100 MHz spectrum?