He was an emeritus professor at the University of Tokyo, where he also took his doctorate degree in Sanskrit in 1954.
He entered University of Tokyo, and majored in Sanskrit and Indian philosophy.
He started visiting in French National Centre for Scientific Research.
After 1962, he became a researcher supported by the Rockefeller Foundation and studied at l'École pratique des hautes études.
His studies included the manuscripts of Dunhuang (Dunhuangologie), but also dealt with other subjects, such as the Tibetan calendar which he published a work in 1973 in Japanese.