Flight Haneda Airport departs from Tokyo Haneda Airport at 14:30 and arrives at Osaka International Airport at 15:35.
The flighttime is about 1h 05m. The distance travelled ("as the bird flies"): 485 Km. So the average speed is roughly 448 Km.
The best day to arrive at Tokyo is Monday and it would be best to avoid Tuesday, as prices are on average 154.51% higher than on Monday. (Average prices, based on 2144108 datapoints.)
We have a lot more statistics for flights JL 121 and between Tokyo and Osaka.