You can never get pastries as good as in France for a simple reason: humidity. It influences the cooking process in such a way you can never get the same texture, and your pastry will become soft within hours of cooking because it soaks ambient humidity.

Pastries in Japan are still quite good, but they can never hope to compare with French ones - they developed their own style and adapted it to Japanese tastes as well, so you can't even expect to get something that has the same taste either, even if it looks alike. And for certain items, you just can't find anything that even matches the supermarket form of it in France : take Pains au chocolat, most of them scream of utter failure in Japan when you bite into them. And I've tried numerous ones, even in expensive bakeries, and was always disappointed.

And let's not forget pastries in Japan are way more expensive than in France. That counts, too.