Sashimi bōchō, literally "sashimi knife" is a type of long, thin knife used in Japanese cuisine to prepare sashimi (sliced raw fish or other seafood). Types of sashimi bōchō include tako hiki タコ引, and yanagi ba 柳刃.

The Kasumi Damascus Yanagi knife 21 cm is a single bevel slicing knife with a long narrow blade that smoothly slices through raw fish and preserves the integrity of each ingredient's freshness.
When preparing sashimi and nigiri sushi, the goal is usually to have cut surfaces that are smooth, shiny, and even in order to maximize the taste. The construction of the yanagiba is designed for this purpose.

Length: The long blade allows the user to cut a block of flesh in a single stroke. This prevents zigzag cutting, which creates a serrated cross section.

Thinness: The blade is very thin behind the edge which allows the cut to be made using primarily the weight of the knife. Greater force or thickness would result in tearing or bruising of the flesh.

Nonstick properties: The back face (urasuki) is concave to easily detach the blade from the substance being cut, and the front bevel (shinogi) allows sliced piece to be easily removed from the blade after cutting. 

Single ground: For right-hand use, the yanagiba has a bevel on the right side and a concave on the left. This allows a more acute angle compared to most double bevel knives and nonstick properties.

Cutting direction: While almost all western knives are used to push and cut, almost all Japanese knives are used pull and cut instead.

Yanagi-ba-bōchō knives commonly range from 210mm to 300mm though there are longer examples than this range. Users can choose the length appropriate to their needs based on the product the knife will be used on and the available space in the kitchen. Typically more length is preferred because it ensures that slices can be completed without resorting to sawing through the protein which can diminish the quality of the final product. 

Kasumi knives are produced by Sumikama Hamono Cutlery in Seki, Japan. Sumikama Cutlery specializes in producing knives from very advanced materials with the most advanced manufacturing techniques.

Kasumi Damascus knives are made of VGold-10 super high carbon stainless steel with cobalt, manganese, molybdenum and vanadium for added durability and ease of sharpening.
The addition of cobalt to the VG-10 steel requires special tempering in order to maximize the full benefit.
The layers on both sides of the VG-10 core are made by repeatedly folding together two different types of SUS410 High Carbon Stainless Steel pounded to 3/1000th of an inch and then "clad" on each side of the VG10 core, until there's 16 exceedingly thin alternating layers.
The edge on a Kasumi knife is beveled at a 15° angle creating a very sharp edge.

The other unique feature of the handle is the design. The oval-shaped handle actually has a ridge at the bottom, increasing control and grip.
Kasumi Damascus series features a pakkawood (wood plastic composite material) handle secured with two stainless steel rivets.
The handle looks and feels like wood, but it is durable, solid and dishwasher safe.

Made in Seki, Japan with a lifetime warranty.