Flight Tan Son Nhat International Airport departs from Ho Chi Minh City Tan Son Nhat International Airport at 23:15 and arrives at Tokyo Haneda Airport at 07:10.
The flighttime is about 5h 55m. The distance travelled ("as the bird flies"): 3910 Km. So the average speed is roughly 661 Km.
There is an 2 hour time difference between Ho Chi Minh City and Tokyo