After the Meiji Restoration, the carrying of swords was banned for the samurai class. Since there was significant industry in providing swords to the samurai, as basic economic theory would tell you, the merchants evolved the product into something else.
That something was the production of knives for professional cooking.
Japanese knives are unique in the world. They are arguably closer to swords than they are to Western knives. For starters, they are frequently, but not always, single-ground (sharpened on exactly one side.) In the modern world, double-beveled knives do exist (e.g. santoku which evolved as a response to the French chef's knife) but the rule still stands.
They are also made to a much harder temper and and seriously sharp. You can cut a piece of paper just by gently caressing it against the blade.
Also, the number and variety of precision knives is far higher than what you would see in a traditional French kitchen. The level of detail and control is far far higher.
Lastly, the tradition of sword-like skills in the kitchen made evolve as a matter of routine, an equally important culture of safety skills. Japanese chefs cut away from the body never towards it. Equally importantly when doing fine fillet-work, the knife will angle away from the body while the top is restrained with the flat-face of the left hand. At all points in time, the blade is kept away from the body. It is quite amazing to watch a master knivesman in action.
Like all highly evolved technical cultures, there's an elaborate array of knives and an elaborate vocabulary to describe their properties, relative merits and demerits but that's just grind for a later post.