The text below seems to be the sole piece of information on the subject on the internet which you probably have already:
After the war, a regular Paris-Tokyo service - often spelt "Tokio" in some countries until the 1950s - was possible. The service was launched on 24 November 1952 by Lockheed Constellation, a more powerful aircraft. It still required three stopovers - Beirut, Karachi and Saigon - and 51 hours of flight!
The service was operated by L749, one then twice a week. It was known as the "Champs Elysées" route. On board, the 34 passengers enjoy a luxury service, with sleeper seats and champagne with their meals. In 1958, the Superstarliner took the "Polar Route" via Anchorage, which was 3,000 km shorter. The flight time was reduced to thirty hours. With the arrival of the jet era, it was shortened even further: 19 hours by Boeing 707 and 12 hours in 1986 with the launch of the non-stop "rising sun" route.
In 2017, Air France operates up to three daily non-stop flights to Tokyo by Boeing 777, with an estimated flight time of 11 hours and 50 minutes!
