Mark with Japanese Mark: 一柳斉　正光 "Ichiryuusai | #458020

一柳斉　正光 "Ichiryuusai Masamitsu". This mark is from a tsuba and was made by Masamitsu, who worked as a sword engraver (soukenkinkou) in Mutsu Province (present-day Fukushima Prefecture). Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons. A tsuba is a sword guard designed to protect the hand from contact with the blade. It also balances the weight of the sword.