Computer programming: data mining, machine learning, cryptocurrencies, network engineering
Finance: international finance, IFRS15, tax compliance, transfer pricing
International law
Medicine/Pharmaceuticals
These are the things that will continue to be relevant for a while. Humanities are good if you aspire to be a professor in your field, but other than that the job prospects are dicey. That isn't to say you can't find decent work, but companies rarely look for poli-sci or history majors.
And yes, fluency or near-fluency in Japanese is an incredibly big bonus - and not just for your career.