Chinese vs. Japanese

Okay so. I've planned to learn an Asian language, but I'm stuck between 2.

These are Chinese(mandarin) and Japanese. I know its sorta biased, but can you guys give me an indication of which I should learn?

I want to go to either country and teach english as a second language, but which would be more "opportunistic?"

I honestly wish the folks who either just started learning Chinese a couple of semesters ago, or have never been taught Chinese would just shut the hell up.
"Chinese is extremely easy" can come from someone who only started learning the language and feels smart because their grammar is easy. Chinese itself isn't easy, it's an outdated language that should adopt a new writing system or else it will be confined solely to China's territory.