Flight Da Nang International Airport departs from Da Nang Da Nang International Airport at 00:20 and arrives at Tokyo Narita International Airport at 07:35.
The flighttime is about 5h 15m. The distance travelled ("as the bird flies"): 3744 Km. So the average speed is roughly 713 Km.
There is an 2 hour time difference between Da Nang and Tokyo