Flight Narita International Airport departs from Tokyo Narita International Airport at 11:20 and arrives at Colombo Bandaranaike International Airport at 17:30.
The flighttime is about 9h 40m. The distance travelled ("as the bird flies"): 6606 Km. So the average speed is roughly 683 Km.
There is an 3.5 hour time difference between Tokyo and Colombo