Erm, if you've had a proper curry recently then you probably will be. Like everywhere else, foreign foods get tailored to their locality or they die. If you fancy a naan filled with sugar and some pretty bland dishes then try an "Indian" restaurant in Japan. Which should come as no surprise, because plenty of other so-called spicy foods here are a) not spicy, and b) surprisingly/sadly, overly sweet.
That's not to say that you can't get a decent curry here, but you'll have to try harder than just walking into a random curry house. And this…
> Indian restaurants outnumber the top 3 pizza chains of the country put together!
I think the only food more maligned by localisation in Japan than pizza could be Mexican food, which leads us back to spice and sugar. I'm not sure what having more curry houses than pizza huts in Japan proves. It would mean something in the US or Italy, but in Japan?
Tastes differ.