Kaimoto was born in Suita on November 26, 1972. After graduating from Tokai University, he joined Japan Football League club Vissel Kobe in 1995. The club won the 2nd place in 1996 and was promoted to J1 League. From 1997, he played many matches. In 2001, he moved to Nagoya Grampus Eight. In 2003, his younger brother Kojiro Kaimoto also joined Grampus. However his opportunity to play gradually decreased. He moved to Albirex Niigata with Kojiro in 2005. Although he played many matches, Kojiro left the club in May 2006. His opportunity to play decreased from 2007 and retired end of 2008 season.
Kaimoto was capped once for Japan national team, when he played a 2000 Asian Cup match against Qatar at the group stage in Beirut on October 20, 2000. He was sent off in the 39th minute in the match. The team went on to win the tournament.