Mark with Japanese mark: 東　益常 "Tou Masuyuki" | #433345

東　益常 "Tou Masuyuki". This mark comes from a "kozuka", the hilt of a secondary knife that is often paired with a Japanese sword, and was designed by Masayuki. Masayuki worked as a "soukenkinkou" in the Nara line of the Saitou house. Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons.