Flight Incheon International Airport departs from Seoul Incheon International Airport at 15:05 and arrives at Osaka Kansai International Airport at 17:00.
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 Seoul is Saturday and it would be best to avoid Thursday, as prices are on average 216.75% higher than on Saturday. (Average prices, based on 1950046 datapoints.)
We have a lot more statistics for flights ZE 613 and between Seoul and Osaka.