The Kensaki Shiribiki is a laminated white steel spear point Japanese marking knife, suitable for left or right registered cuts, at 15mm wide it is a nice medium size with a comfortable weight in the hand.
The maker Ikeuchi Hamono was founded in 1953 by Shozo Ikeuchi, who at the age of 12 became a disciple to a master swordsmith serving an 8 year apprenticeship before setting up on his own. The company now has three generations of family members working together to produce beautiful quality cutting implements, either as one-off commissions or small batch handmade production.
When sharpening try to keep as much of the back as possible registered on the stone and apply pressure over the bevel to avoid creating a belly. Don't forget to ease the sharp edges on the sides of the knife to avoid cuts to the fingers in use.