Nagasone Kotetsu was a Japanese swordmaker of the early Edo period. Kotetsu was born in Sawayama around 1597, and was first known as Nagasone Okisato. His father was an armorer who served Ishida Mitsunari, the lord of Sawayama. However, as Ishida was defeated by Tokugawa Ieyasu at the Battle of Sekigahara, the Nagasone family and some other craftsmen from Sawayama went to Echizen province, where they took refuge in Fukui city.
