Flight Haneda Airport departs from Tokyo Haneda Airport at 02:00 and arrives at Seoul Incheon International Airport at 04:50.
The flighttime is about 2h 50m. The distance travelled ("as the bird flies"): 1487 Km. So the average speed is roughly 525 Km.
The best day to arrive at Tokyo is Wednesday and it would be best to avoid Saturday, as prices are on average 107.55% higher than on Wednesday. (Average prices, based on 1605039 datapoints.)
We have a lot more statistics for flights KE 720 and between Tokyo and Seoul.
