In 1958, due to his knowledge in history and religion of the region, he spent three months as a Buddhist priest at the Wat Bowonniwet temple in Bangkok.
From there, he traveled to such countries as Cambodia, Laos, Thailand and Vietnam in each one of which he studied cultures of those nations.
In 1963 he returned to his native land to continue his work at the Ministry of Foreign Affairs and two years later got hired by the Center for Southeast Asian Studies where he pursued his academic career.
During that time, he wrote and published a five-volume book called The Computer Concordance to the Law of the Three Seals, and was relocated to the Institute of Asian Cultures which was a part of Sophia University where he taught till 1993.
Next year he was awarded Fukuoka Prize and is currently works at the 13th Congress of the International Association of Historians of Asia.