How different is Japanese SEO from US/EU SEO?
The principles of SEO are the same regardless of language. However, simply translating a site, keywords and meta tags into another language often results in poor SEO, unless the translator is SEO trained and capable of writing SEO copy. Different language means different society. A language reflects culture, history, way of thinking, life style, and trends of a society. Language evolves and word usage changes faster than dictionaries catch up, especially in areas like technology and fashion. So it is critical to do a keyword research and study competitors sites in the language you are translating your site into before writing copy in that language. But if you have already translated your site into Japanese and not sure if the translation is good in terms of SEO, we are happy to take a look and see if it needs fixing.
One thing particular about Japan SEO is that you need to SEO your site both for Yahoo Japan and Google, since Yahoo Japan is used more than Google in Japan. Unlike other international branches of Yahoo, Yahoo Japan is an independent company owned by Tokyo based Softbank. It offers most features of Yahoo but also carries its own programs and features.