Flight Haneda Airport departs from Tokyo Haneda Airport at 15:40 and arrives at Guangzhou Guangzhou Baiyun International Airport at 19:25.
The flighttime is about 4h 45m. The distance travelled ("as the bird flies"): 3038 Km. So the average speed is roughly 640 Km.
There is an 1 hour time difference between Tokyo and Guangzhou