Flight Haneda Airport departs from Tokyo Haneda Airport at 07:25 and arrives at Kagoshima Kagoshima Airport at 09:30.
The flighttime is about 2h 05m. The distance travelled ("as the bird flies"): 1048 Km. So the average speed is roughly 503 Km.
The best day to arrive at Tokyo is Monday and it would be best to avoid Thursday, as prices are on average 133.62% higher than on Monday. (Average prices, based on 396263 datapoints.)
We have a lot more statistics for flights SN J71 and between Tokyo and Kagoshima.