Flight Haneda Airport departs from Tokyo Haneda Airport at 14:05 and arrives at Fukuoka Fukuoka Airport at 16:00.
The flighttime is about 1h 55m. The distance travelled ("as the bird flies"): 1048 Km. So the average speed is roughly 547 Km.
The best day to arrive at Tokyo is Sunday and it would be best to avoid Wednesday, as prices are on average 333.5% higher than on Sunday. (Average prices, based on 3280217 datapoints.)
We have a lot more statistics for flights JL 321 and between Tokyo and Fukuoka.