Glancing at the unassuming corner complex located at 2487 Spring Street, one would have no clue as to the amazing feats of strength and skill being honed within suite #6. This is the Kodenkan Martial Arts Institute, in operation since 1976, making it one of the oldest martial arts schools (or dojos) in Northern California. Kodenkan specializes in DanZan Ryu, a particular form of jujitsu.