Flight Incheon International Airport departs from Seoul Incheon International Airport at 13:20 and arrives at Tokyo Narita International Airport at 15:55.
The flighttime is about 2h 35m. The distance travelled ("as the bird flies"): 1555 Km. So the average speed is roughly 602 Km.
The best day to arrive at Seoul is Sunday and it would be best to avoid Wednesday, as prices are on average 289.02% higher than on Sunday. (Average prices, based on 5619918 datapoints.)
We have a lot more statistics for flights 7C 1114 and between Seoul and Tokyo.