I don't know, I guess it depends on the word. In the case of Anime, I personally use it to refer to the art style, not the fact that its animated. I don't usually talk about anime cartoons 'caue it's redundent.

But in general, its Ok to use a forgein word if it's more accurate than the standard English equivilent. Hijab is a perfectly legitamate word to use because it's simple more accurate than "headscarf" because hijabs are religious in nature, while headscerves aren't. I can't imagine anyone referring to a yarmaluke as a "beanie", it isn't accurate. You could go around calling burritos "wraps" but I'm not sure that would convey the whole picture.

I think you should favor accuracy. If you're specificaly referring to a japanese style of special effects, then Tokusatsu might be the right word to use. I don't get the whole "Kawaii" "Desu" stuff, though. It seems kinda strange to want to learn random words in another language.