Hiroo Mochizuki was born on March the 21st 1936. He is 8th dan of Aikido, 8th dan of Ju jitsu, 7th dan of laido7th dan of Karaté and 3rd dan  of Judo.

In 1950, he starts training Judo and Aikido with his father. Between 1957 and 1958, he travels to France to teach Sotokan karaté wth master Henri Plée. He is the first japonese to introduce Karate in Europe.

In 1958 he takes part in the creation of the French Federation of Aikido, Tai Jutsu and Kendo. At the same time he teaches Shotokan Karaté and Aikido.

After getting his Veterinary diploma in 1962, he is sent to France by his father (Minoru Mochizuki), by request of Alain Floquet, to take the place left by Jim Alcheik. In 1964 , he became the first technical counselor to the sections of Karaté and Aikido of the FJDA.

In 1970, as a tribut to his father, he creates the "YOSEIKAN BUDO'' School. Later,   in 1975 he creates The French Federation of the Yoseikan Budo.