Flight Kansai International Airport departs from Osaka Kansai International Airport at 14:00 and arrives at Seoul Incheon International Airport at 15:55.
The flighttime is about 1h 55m. The distance travelled ("as the bird flies"): 1002 Km. So the average speed is roughly 523 Km.
The best day to arrive at Osaka is Monday and it would be best to avoid Thursday, as prices are on average 103.58% higher than on Monday. (Average prices, based on 6391238 datapoints.)
We have a lot more statistics for flights KE 728 and between Osaka and Seoul.