The first Japanese to obtain his pilot's licence from the Aéro-Club de France, he is credited with having made the first flight in a powered aircraft in Japan in 1910.

On orders of the Imperial Japanese Army General Staff, he purchased a Farman III biplane, which he shipped back to Japan.

Also in 1911, several more aircraft were imported and an improved version of the Farman III biplane, the Kaishiki No.1, was built and flown by Tokugawa in Japan.

The Provisional Air Corps consisting of four Maurice Farman MF.7 biplanes and a single Nieuport VI-M monoplane flew 86 sorties between them.

Tokugawa came to be known in Japan as "the Grandfather of Flight"[8] He entered the active reserve in 1939 and was awarded the Grand Cordon of the Order of the Rising Sun in 1940.