Mark with Japanese Mark: 水府住　一柳友寿刻 "Suifu ju | #458291

水府住　一柳友寿刻 "Suifu ju Hitotsuyanagi Tomonaga kizamu". This mark is from a kozuka, which is the hilt of a small, secondary knife. It was made by Tomonaga, who worked as a sword engraver (soukenkinkou) in Hitachi Province (present-day Ibaraki Prefecture). Soukenkinkou is the Japanese name for metalworkers who design accessories for bladed weapons.