Walter Takeshi Yamaguchi Sensei was born in Los Angeles, California on April 15, 1938. He and his family were incarcerated at internment camps during World War II, starting with Manzanar, then moving to several other camps, and ending up in Texas. At the end of the war, he and his family went to Japan. He later returned to the United States by himself as a child.

Yamaguchi-ensei started Kendo and Iaido in January of 1962 at West Los Angeles Dojo, and later began studying under Torao Mori Sensei. In 1964, he and his brother, Makoto, helped Hara Sensei establish Norwalk Kendo Dojo. At the time, Yamaguchi-sensei held the rank of 2 Dan and was a junior instructor. By the 1970s he became 4 Dan and continued to achieve ranks through 1988 when he received the rank of 7 Dan, Kyoshi.  He also held the same rank in Iaido.

Yamaguchi Sensei’s contributions have been indispensible to the growth of kendo and iaido in California, as well as, in the United States. He not only helped co-found Norwalk Kendo Dojo, but also Covina Kendo Dojo in 1968 and Costa Mesa Kendo Dojo in 1975. Both he and his brother were members of Team USA for the 2nd World Kendo Championships (WKC) in 1973. He was the coach for Team USA in the World Kendo Championships in France in the 1985 WKC. He served as President of the Southern California Kendo Federation (SCKF) and was a member of the Board of Directors of the All United States Kendo Federation (AUSKF) for many years. He has mentored many people who have held offices on the SCKF Board. The Southern California Iaido Association (SCIA) was founded by Yamaguchi-sensei, who also served as its head instructor and advisor. He was also the first Iaido sensei for most of the founders of the Northern California Iaido Association (NCIA).

Yamaguchi Sensei became the head instructor at Norwalk Kendo Dojo in 1973 and held the position through 1983. With all his time spent with the various organizations and splitting his time between Kendo and Iaido, he made sure the students at his own dojos felt they had his attention and his guidance. He would say, “do it naturally”.

Yamaguchi-sensei spent 50 years of his life practicing, teaching, and shaping Kendo and Iaido in the United States. He enjoyed the travel opportunities that come with his advisory roles and liked to travel with his friend Arthur Murakami-sensei. He loved taking pictures and in the later years, he could be remembered with camera in hand at tournaments and holiday parties. He passed away at Norwalk Kendo Dojo October 5, 2012, just before the start of practice, about to do the thing he loved.