Flight Kansai International Airport departs from Osaka Kansai International Airport at 16:15 and arrives at Seoul Incheon International Airport at 18:25.
The flighttime is about 2h 10m. The distance travelled ("as the bird flies"): 1002 Km. So the average speed is roughly 462 Km.
The best day to arrive at Osaka is Saturday and it would be best to avoid Friday, as prices are on average 266.28% higher than on Saturday. (Average prices, based on 5287557 datapoints.)
We have a lot more statistics for flights RS 714 and between Osaka and Seoul.