Um, yeah
Firstly, Americanos pay tax on their worldwide income. You get an exclusion but pay full tax after that. Overseas retirement plans are not recognized by the U.S. so that will be taxed at 30%. It's a big deal and a lot of folks get caught out with this when the tax bill comes. Honestly, working overseas as an Americano is a pain in the arse! Japan gets really cold and windy too. Bonuses are income!
Secondly, 10 ID90s a month is low as opposed to working for a U.S. regional with unlimited pass benefits (KCM and Jumspeat as well) included. You cannot beat KCM and CASS Jumpseat. So, you have to come up with something equivelant, ie; PAY! The pay is low.
My point; the contract falls well short for the kind of people they really need. Going to Peach, MAYBE, after four years just falls short. Also, you'll get reimbursed for your trip but you have to travel to Japan in economy class and make your own travel arrangements! In today's day and age that is simply offensive and say's what they really think of you.
Not an attack on the post or poster but FYI about the deal. You can all check my information. Expat deals always come with some sort of trick. It's the fine print you must pay attention to.