Earlier quoted context omitted.
Slightly off-topic: I had ramen a few times in Japan, and while truly delicious, it's massively expensive and rather exotic. Why is ramen a synonym for "cheap" in the US (apparently)? Or does it mean just "instant noodles" over there?
The US of A has a greater capacity to produce grains needed to produce the noodles, and can deliver them to market without having to put them on a boat. Japan has less arable land, so less grain producing land, and (probably) has to import more (which requires boats).
And more importantly, a greater capacity to subsdize production of said grains.
Edit: Did this comment really get greyed out? The mechanism for that is still kind of mysterious to me. Let me clarify, I don't mean the US has more money, just a dumber system of farm subsidies.