Mark with Japanese mark: 竜青眠 "Ryuseimin" | #433157

竜青眠 "Ryuseimin". This mark comes from a "kozuka", the hilt of a secondary knife that is often paired with a Japanese sword, and was designed by Ryuseimin. Ryuseimin 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.