I know some Chinese, having worked in China for a number of years. Maybe Japanese will be easier for me.
By banking, I meant that since I intend to do investment banking, either on the business side or as a legal counsel, I hope to learn a language that will help me most in the career. Since Germany is the 3rd largest economy, and Japan second, Japanese and German seem like idea languages.
I don't know what French is good for in the financial world, UN has 6 official languages, English, Russian, French, Chinese, Arabic, Spanish. The office of secretary general I believe uses French or English.
Sorry, you're right. Whenever I looked at legal affairs employment opportunities on the UN site, it seems to encourage English or French.
If you already know some Chinese I'd stick with that. Japanese might be easier to learn once you know the kanji in Chinese first.