United Airlines has low fares at $486 round trip from Los Angeles to Tokyo NRT nonstop for flight departures in October and November. You can also fly to Tokyo Haneda on a one-stop itinerary via San Francisco SFO for $490-$500. This appears to be a challenge to Xiamen ticket prices at $419 round trip for one-stop tickets via Xiamen, China.
Lowest ticket prices with UA/ANA are Tue-Wed-Thu departures.
United Airlines on ANA operated flights
LAX – Tokyo NRT – LAX