[Ren Ren]

In the Ainu language, these knives are called "puriki makir" - a beautiful or ornate knife. They were part of the festive costume. Old knives are a rarity, for a long time the Japanese authorities pursued a policy of assimilation of the Ainu and forbade them to maintain their cultural traditions. To my knowledge, less than twenty craftsmen now make traditional knives, and they use mostly Japanese-made blades.
Two Japanese symbols are depicted on the scabbard - a chrysanthemum with 16 petals and three commas inscribed in a circle "mitsudomoe". Chrysanthemum of this type is the emblem of the imperial family, until the end of WW2, its use by private individuals was strictly prohibited. My guess is that 1945 may be the earliest date for this knife.