Non-stop flight time from Bangkok to Tokyo is around 6 hours Fastest one-stop flight between Bangkok and Tokyo takes close to 8 hours . However, some airlines could take as long as 28 hours based on the stopover destination and waiting duration.
Main Airlines Japan:
All Nippon Airways
Main Airlines Thailand:
Biman Bangladesh Airlines
Both Airports are very modern and provide many facilities for you to enjoy whilst you wait for your flight.
Bangkok Airport - Thailand:
Haneda International Airport - Japan