Flight International Airport departs from Osaka International Airport at 20:15 and arrives at Tokyo Haneda Airport at 21:25.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 485 Km. So the average speed is roughly 416 Km.
The best day to arrive at Osaka is Tuesday and it would be best to avoid Friday, as prices are on average 39.03% higher than on Tuesday. (Average prices, based on 1855547 datapoints.)
We have a lot more statistics for flights JL 138 and between Osaka and Tokyo.