SkyTeam Alliance airline Xiamen and Star Alliance member Air China have Los Angles to Tokyo on sale for $420 to $450 round trip.
Xiamen Airlines has the lower fare at $420 for LAX-Xiamen XMN – Tokyo Narita NRT on travel departures from October through next March.
Air China has a competitive fare to Tokyo Haneda at $449 to $490 round trip via Beijing PEK. Lower ticket prices at $449 are available in 2017 and higher ticket prices around $490 were found for 2018 flights.
Xiamen Airlines $419.65 round trip Expedia.com ticket
Los Angeles LAX – Xiamen XMN – Tokyo Narita NRT – XMN – LAX
Sun Nov 12 – Tue Nov 21
Los Angeles LAX – Beijing PEK – Tokyo Haneda HND – PEK – LAX
Wed Nov 15 – Wed Nov 22