Not sure what city in Japan is "livable" at 2,490,000 yen annual salary.
this was several years ago, but i made about that working retail in osaka and it was fine. english teachers don't make much more.
I work with someone who one time had to entertain business guests from Japan. They purchased the most luxurious option they could for a train ride between Boston and New York. They were utterly disgusted. It was the equivalent of the budget option to them.
there are definitely japanese subways and regular railways that feel more legit than first-class train travel in the west.
but regular nozomi shinkansen is pretty much the epitome of luxury travel to me. near-infinite legroom, shop with beer and bento boxes on the platform, super fast, no-one bothers you, actual views out the window, no check-in or baggage claim, you can just show up whenever and get a ticket for a train in the next 20 mins, etc.
for like $120 one-way tokyo to osaka or kyoto (which takes a little over 2 hours), it's generally worth it when flying from narita is about $80 on an LCC.
the funny thing is that the "first class" cars on a regular shinkansen aren't that much more luxurious than the standard ones.