NIWA NAGASHIGE (1571-1637) Son of Nagahide. He served Toyotomi Hideyoshi and fought at the Battle of Nagakute. He sided with Ishida Mitsunari during the Sekigahara campaign. He would go on to serve Tokugawa Ieyasu during the siege of Osaka where he reinforced Uesugi Kagekatsu trying to hold on to Shigino fort.
Hamon (from Japanese, literally "blade pattern") is a visual effect created on the blade by the hardening process. The hamon is the outline of the hardened zone (yakiba) which contains the cutting edge (ha). Blades made in this manner are known as differentially hardened. This difference in hardeness results from clay being applied on the blade prior the cooling process (quenching).