Flight Kansai International Airport departs from Osaka Kansai International Airport at 21:00 and arrives at Tokyo Narita International Airport at 22:15.
The flighttime is about 1h 15m. The distance travelled ("as the bird flies"): 582 Km. So the average speed is roughly 466 Km.
The best day to arrive at Osaka is Wednesday and it would be best to avoid Monday, as prices are on average 94.42% higher than on Wednesday. (Average prices, based on 8294954 datapoints.)
We have a lot more statistics for flights NH 98 and between Osaka and Tokyo.