If you think that you only need to use any kind of knife for all the slicing requirement that you need in the kitchen, then you are in for a surprise. Different dishes require for different sets of kitchen utensils. Take for example Japanese cuisine. They are known for their sashimi and sushi, foods that are basically raw and sliced with precision. With this you need special sushi knives for the different kinds of sushi that you plan to serve. There’s a knife for fish, different knife for squid and yet another different sushi knife for puffer fish. Even beef or chicken have their own specialized sushi knife.
Sushi knives are not your ordinary knife where both sides of the knife are sharpened. It is believed that sharpening only one side makes a much cleaner cut which is a necessity, as far as aesthetic is concerned, for Japanese cooking. Just like any other specialized craft, using a sushi knife that is sharpened only in one side takes dedicated practice.
Professional Japanese chefs value their sushi knives so much that it is common practice not to allow other people use your own set. A good set of knives is a must in any Japanese kitchen thus they invest in the best quality that they can afford.