I am fluent in Japanese, and now working in Shanghai. I would take Tokyo over Shanghai anyday as a place of employment or to live. I'd say you'd be more inspired there. But is Tokyo the best place? I have not covered the entire world, but with the exposure I have I had, it would rank high. In the end, the reason for locating in a place determines the value and preference. So, choosing a language is fine, but this language preference has to be driven by other factors in life.