[Columbine]

Not sure what you mean by 'english curry', but curry is dead easy to make in Japan with a little investment in some spices.

Your average curry-from-scratch is simply

meat,
onion (diced)
chili (chopped)
garlic (crushed)
other veg (diced)
tomato paste

and maybe lentils or something for bulk.

if you take yourself off to the su-pa and hunt around you can usually get enough to make up a garam masala; cumin, cinnamon, nutmeg, cardamon, black pepper, cloves, coriander seed and bay leaves. if powdered, mix up each time you make a curry, if whole-spices you can measure out the proportions and shove it in a jar. Or make up your own dry mix by adding and taking what you like and don't like. You can also make wet spice pastes with the onion etc already incorporated and freeze them in portions.

But seriously, Japan is much better situated for getting hold of fresh spices than the UK is. I have never seen fresh galangal in a british supermarket (that wasn't a specialist). It was frequently on sale in both Sanko and Topworld in Osaka.