It's a combination of factors which make both successful in their home markets and less so in others. Couple of main ones are that the 360's biggest appeal is it's fps games which don't appeal to the japanese gamers and second is obviously brand and the image that comes along with that.

While sony managed to win over the american market with the ps2 last gen, microsoft still faces a huge obstacle in japan. Although to their credit they have made a greater efort this gen with a number of good rpgs.

Why ? because XBOX 360 doesn't have the License of Mario, Zelda and for sure Final Fantasy that's all !!!

i'm not japanese, but the games on 360 not interests me too
the only exclusive game i like is "ace combat" (maybe "Lost Odyssey" too), you sell me a brand new 360 for $100 i wouldn't buy it

no matter how "good" Halo, Gears of War...are, hey i dont play FPS!

Is Starbucks good? i dunno and dont bother to try.
i dont drink coffee with milk and sugar
if i want some milk and suagr i will have a cup of milk tea

They're getting close to being a contender with the next Xbox.

See http://vgchartz.com/hwlaunch.php?cons1=X360&reg1=Japan&cons2=XB&reg2=Japan&cons3=XB&reg3=Japan&weeks=156&weekly=1

At this point after the Xbox launch, sales were close to zero. The X360 actually has measurable sales.

Because Japan is used to buying Japanese consoles. SEGA, Sony, and Nintendo are all Japanese.

Microsoft is not.

Hmm.

As many people have stated microsoft is pushing the boat out in japan with games tailored specifically for that audience (blue dragon etc), but it still has a negative image based on the last xbox, poor marketing in that area and the fact most people construe it as being good for only FPS'.

The fact of the matter is, the biggest franchises in Japan are either exclusive to other consoles (FF, Mario, Zelda, KH etc), or are multi-platform (with the PS3 generally) and will be bought on the more familiar Sony console (Dynasty Warriors, Pro Evolution).

Japan took a small bite with Halo 3 which saw quite a large spike (in terms of average weekly sales), but this has died down pretty quickly. As has been stated before its a marathon, not a sprint, MS will keep slowly increasing their install base in japan, so the next console released over there will have a much more favourable reception.

becuase japan likes to play anime baised games and Xbox360 dosent have many of those

DS has the most anime games and that is why its doing the best 

I have a japanese friend and i asked him why the xbox is so unpopular and he said he doesn't like it just because it's American, although that's probably one of many reasons

the main reason is the games for xb360 is too computer-like games...
most are FPS....


the ONLY reason!!