Flight Kansai International Airport departs from Osaka Kansai International Airport at 18:25 and arrives at Tokyo Narita International Airport at 19:55.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 582 Km. So the average speed is roughly 388 Km.
The best day to arrive at Osaka is Saturday and it would be best to avoid Monday, as prices are on average 103.86% higher than on Saturday. (Average prices, based on 8276863 datapoints.)
We have a lot more statistics for flights JQ 208 and between Osaka and Tokyo.