Right after the War Seigo Yamaguchi dissolved his military unit and went back to home, Fukuoka. His interests were towards national matters or international affairs and he succeeded to pass the first national examination to be a senior public officer in Japanese government. Alternative choice was to be a member of one of major constructing company (generally speaking it is considered very good in Japanese society to work in big company). He finally decided to go abroad and probable destination was Europe and especially France. At that moment one of his father's friend who was a founder of Macrobiotics advised him to master some Japanese traditional culture before going abroad.

Meet with the founder of Aikido, Morihei Ueshiba Sensei

Then Seigo Yamaguchi had got two letters of recommendation and introduced himself to the founder, Morihei Ueshiba (O-Sensei). It was destined encounter of the amazing person and he decided to be a student (Uchi-deshi) of O-Sensei, but this personal choice was quite unusual at that moment because many of Japanese were struggling with acquiring foods after their defeated national environment and nobody looks after Budo. Moreover Budo was officially forbade by the US officials. It was also unique to specialize in Aikido as Uchi-deshi without having any other job and it means that he became the first professional of this budo. Gradually this budo became known and he started to teach it not only at Honbu dojo but also at many places such as Japanese Defense Agency, Meiji University, Tokyo University, other public Dojos and so on. Obviously Seigo Yamaguichi played very important role in the development of Aikido.