Career
He was a considered to be a groundwork expert. Isogai was born in Nobeoka, Miyazaki Prefecture, Japan on October 26, 1871. He was the eldest son of Tsunehisa Isogai (磯貝 恒久, Isogai Tsunehisa), hanshi of Sekiguchi-ryū jūjutsu in Nobeoka.
In 1891 he moved to Tokyo and joined the Kodokan where he studied judo with Jigoro Kano.
In 1893 he became judo teacher at third high school in Kyoto. In 1899, he was appointed professor of Judo at Dai Nippon Butoku Kai.
Isogai was promoted to tenth dan, the highest rank in judo, on December 22, 1937. He was the second person to be awarded this grade and the first living person to be presented with lieutenant
