Sujihiki means sushi slicer in Japanese. The Sujikiri is a long symmetrically curved blade is designed to slice sushi rolls and battera sushi in one rolling slice without crushing them. These knives are particular popular in the Kansai (Osaka and Kyoto) regions.
Some types of sushi are made in long pressed bars (“oshisushi”) or thick rolls (futomaki) and sliced, just before serving, into smaller portions. Slicing though the fish ingredients should also ays be done in a single stroke and any nori seaweed should remain dry and brittle, so it is tough to cut with anything but the sharpest blade.
The main rice body has a rather sticky texture that quickly builds up on the blade, which therefor requires constant wiping with a wet cloth. Both the yanagiba as well as the sujihiki knife can do the job and have evolved for the purpose of cutting rolls or bars of sushi for this elegant presentation.