Kenkichi invented 'Yamatozue, ' a wooden sword with a lock with which to hang it from one's belt (and which he called 'tsue' (stick), though different from 'jo' used in jujutsu, out of consideration for the government) to replace 'Uchigatana' (a Japanese sword) as well as 'Ganko Ogi,' a wooden fan which was a substitute 'Wakizashi' (short sword).
鍵吉は、打刀代わりの「倭杖」(やまとづえ)と称する、帯に掛けるための鍵が付いた木刀（政府に遠慮して杖(つえ、杖術で使用する「じょう」ではない)と称していた）と、脇差代わりの「頑固扇」と称する木製の扇を考案した。