Nimai(Two Piece) is the Japan's traditional approach to the kitchen knife making, this construction method is typically found on knives with native Japanese origins like Yanagiba, Deba and Usuba. When constructing a Nimai knife, a piece of soft cladding metal will be placed onto a core steel, the two pieces of metal are then forgewelded and shaped into the knife.

The Nimai knives are usually sharpened in single-bevel fashion, with hardened core steel exposed on the flat/hollow-ground side and soft cladding warping over the other side and over the spin. The soft cladding offers support for the harder yet more brittle core steel so the knive can have a thin, sharp edge while have some overall strength. Since the single bevel Japanese knives usually don't have a secondary bevel, the combination of soft cladding and hollow-grind have made the sharpening process easier than Monosteel and Honyaki knives.

The typical traditional Japanese kitchen knives have few features: Nimai construction, single bevel, carbon core steel and soft iron cladding. Some knifemakers have made a small twist to this classical formula, by introducing forged damascus soft iron to Nimai's cladding, the timeless look now has a pop of beauty and complexity added to it. However, the core and cladding are still prone to rust, so to maintain these handmade beauties, more attention and care shall be needed from their owners.

The etching process starts with the knife being thoroughly cleaned to remove any oils or residues. A protective mask may be applied to the areas not intended to be etched. The blade is then submerged in an acidic solution, such as ferric chloride, which reacts with the different layers of steel at varying rates. This creates a layer of dark oxide on the surface of the blade where the thickness of the oxide varies according to the reactiveness of the steel. After etching, the knife is neutralized in a baking soda solution, rinsed, and dried. The final step involves polishing the blade to highlight the etched design, enhancing both the knife's beauty and showcasing the craftsmanship of its maker.