http://kotaku.com/5336183/xbox-360-games-on-demand-region-locked
Yeah, I had seen this coming. First problem was that the games were not valued by Microsoft Points, as originally intended. This means that I would need a Japanese credit card with valid address and everything, should I want to digitally download any Japanese games. Strike 1.
Next, even if I did have the access, if you see the link above, you won’t be able to download US games outside of the US. Strike 2.
Lastly, the Xbox Originals are not region locked. Strike 3.
So clearly, M$ is not sure what the hell their strategy is with Games on Demand…