Mark with Japanese mark: 武州住　正齊 "Bushu ju | #433573

武州住　正齊 "Bushu ju Masanari". This mark comes from a "tsuba", a sword guard designed to protect the hand from contact with the blade and an opposing sword. It was made by Masanari, who worked as a "soukenkinkou" in the Nara line of the Hashimoto house. Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons.