Seiichiro Kashio

Seiichiro Kashio was from Osaka, but graduated from the Tokyo High School of Commerce and worked for the Mitsui trading company at its New York branch. Later, he joined the raw silk department of the company in Yokohama. He competed at the 1918 and 1919 US Championships, losing in the third round in 1918 and second round in 1919. At the 1920 Olympics Kashio competed in singles and doubles, losing in the third round of singles, but he and Ichiya Kumagae won the silver medal in the doubles. Kashio played two ties in Davis Cup for Japan in 1923, winning one of two matches. He was also Canadian singles champion in 1919.

In 1934, he became a Vice-Chairman of the All-Japan Student Tennis Federation and a director of the Japan Tennis Association. Working in Seattle, when the Pacific War broke out between Japan and the United States, Kashio was detained by the authorities due to the outbreak of the Pacific War. In 1942, he returned with the detainee exchange ship Asama Maru. After World War II, he initially worked as a standing auditor for Mitsui before joining Takahashi Shokai as managing director.