Not true!!!
American Movies have a huge hold over Jap. Audiences.
American Food is very popular in Japan, in some cases more than the local cuisine.
American Music is a Rage in Japan.
Japan's Most popular Spectator Sport is "Baseball"
America's Education system has influenced Japans.
Also a lot of American culture has rubbed on to Japan, Christmas is a huge festival, although Santa is an old man on the Moon. :-p
Jap Businessmen play Golf on their spare time.
Jap's dress in Suits, rather than kimono's..
Well I could go on, but the reason X360 has flopped in Japan, is because it has very few games that appeal to the Jap audience. the same reason dreamcast flopped in japan.
I seriously doubt X360 will ever reach 1M consoles sold in Japan during its lifetime. But us still an improvement over the Xbox which failed to crack into 500K sold during its lifetime. 500K before 2008, might be possible.
We have 16 weeks, at a highly optimistic average of 5000/week (its 1500/week right now) hey would hit 80K. 440K+80K would just help them scrape through. Although sustaining 5K/week in japan is a tall order for the 360.