It isn’t easy to do, and don’t try it at home unless you want to cut your wrist or hand off. The skill of a chef is mostly in his knife. This knife is razor-sharp and balanced in the right hands. This is what we call Tsuma, a word that denotes several meanings, but in this case it refers to daikon (Japanese Radish) being peeled and then very thinly sliced and used for sashimi. It almost always accompanies sashimi and is 100% edible.