He played for Waseda WMW, which consisted of players and graduates of his alma mater.
In May 1934, when Kawamoto was a Waseda University student, he was selected Japan national team for 1934 Far Eastern Championship Games in Manila.
[2] On May 3, 1954, he made history by becoming the oldest player to play for Japan national team at the age of 40 years and 106 days.
In 1956, Kawamoto served as assistant coach under manager Shigemaru Takenokoshi for 1956 Summer Olympics.
In 1958, Kawamoto named a manager for Japan national team as Hidetoki Takahashi successor for 1958 Asian Games in Tokyo.