This is a small knife used for carving small objects. It's a version of the intō (seal-carving knife) used for making Ise netsuke, with a sheath added. It uses Enju (Japanese pagoda tree) wood, and the mekugi (peg) is made of ebony. When sharpening, you can remove the mekugi to take out the blade, allowing you to sharpen it without dirtying the sheath. The steel used is Aogami No. 2 (Blue Paper No. 2).