Almost everyone I've met from the Netherlands is fluent in English, and has a better grasp of English grammar than many Americans. I wonder why their result is so much better than the Japanese. There could be many reasons for this, including that English and Dutch are much closer than English and Japanese, that the Dutch have more contact with English-speaking people and media, or that the Dutch schools have a better way of teaching language than the Japanese schools. I've also found this to be the case with younger Germans.
And it's all based on study and test taking.