I've made this trip! Flying from Toronto to Hong Kong takes about 15 hours. Flight from Hong Kong to Manila is about an hour and 45min. So a total flying time of about 17hrs. Returning I flew from Manila to Tokyo - 4hrs and then to Toronto - 13.5hrs. A total flying time of 17.5hrs. Going back was an easier trip.
For direct flights, about 8.5 to 9 hours flying time.
The flight time from Osaka, Japan to Tokyo, Japan is about 30 minutes.
For direct flights, about 2.5 hours flying time.
9 hours
For direct flights, about 10.5 to 11 hours flying time.
For direct flights, about 10 to 10.5 hours flying time.
The flight time from Toronto, Canada to Paris, France is about 7.5 hours.
1.5 hours
For direct flights, about 9.75 hours flying time. This is time 'in the air' and excludes ground activities.
The flight time from Nanjing, China to Tokyo, Japan is about 2 hours, 27 minutes.
From Toronto to Germany (Frankfurt) approx 6 hours with a tailwind.