Mark with Japanese mark: 竜青眠 "Ryuseimin" | #433159

竜青眠 "Ryuseimin". 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 Ryuseimin, who worked as a "soukenkinkou" in the Nara line of the Kawano house. Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons.