Mark with Japanese mark: 昇行堂　砂川 "Shoukoudo | #433488

昇行堂　砂川 "Shoukoudo Sunagawa". 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 Masakichi, who worked as a "soukenkinkou" in the Nara line of the Suangawa house. Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons.