Mark with Japanese mark: 龍法眼一男　源壽勝 "RyuHougen | #433186

龍法眼一男　源壽勝 "RyuHougen kazuo Minamoto Toshikatsu". 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 Toshikatsu, who worked as a "soukenkinkou" in the Nara line of the Tanakatouryuusai house. Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons.