In preparing sashimi and sushi, there are very important conditions that the sliced cross section be smooth, shiny and sharp in a microscopic view. Those conditions cannot be met by other usual knives. Yanagi-ba-bocho is especially designed to satisfy the conditions.
The Sujihiki is intended for slicing boneless protein. The short height of the blade creates less friction when slicing and the blade draws through fish and meat effortlessly. The sujihiki is kind of a Western style equivalent of the traditional Yanagiba knife. A Sujihiki is double bevel while a Yanagiba is Single Bevel.