Both top notch airlines, Singapore and JAL with partner American Airlines have round trip airfares travelling from Los Angeles (LAX) to Tokyo (NRT) for $597 including taxes and fees. This is nonstop service.
Price comparison: As of right now, Air China, 3/5 Star rated with Skytrax, have this for $50 cheaper but it makes a stop in Beijing. Other airlines with same nonstop flights are pricing out at $777 or more. My thoughts…this has been under $500 before and that deal was without planning ahead (or short notice). You can wait for it to be under $500 again but be ready to travel or do this deal and plan ahead.
Travel Availability:
Departures available every Sunday, Monday, Tuesday, Wednesday Thursday beginning Aug 30 thru Dec 6, 2017. Wide returns available.
Use those dates and plug into Orbitz , CheapOAir or Expedia to see which airline is flying on your choice of dates.
You may also book directly with American or Singapore Air