Please be aware that Bangkok and Tokyo has multiple airports and that these results are for all airports serving the city.
The best month to fly between Bangkok and Tokyo is November and the most expensive month to fly is April. (Average prices, based on 558 datapoints.)
The best day to arrive at Bangkok is Wednesday and it would be best to avoid Friday, as prices are on average 45.59% higher than on Wednesday. (Average prices, based on 347 datapoints.)
The cheapest airline flying from Bangkok to Tokyo is Thai Airasia X . They are 76% cheaper than All Nippon Airways. (Average prices, based on 568 datapoints.)
The best time to fly is at around 1. (Average prices, based on 963 datapoints.)