This is a carbon steel knife. Carbon steel is expected to develop a dark patina with use. It needs to be hand washed and dried immediately after use. Do not air dry. Do not put it in the dishwasher. Long exposure to moisture and debris will result in rust. Any rust development should be removed with a light abrasive.

Twisting, scraping, and heavy use, as well as use on hard and very dense objects can lead to edge damage. Use on a quality wooden cutting board will help the knife stay sharper for longer. Use on hard surfaces like plates and bamboo will reduce the edge life and can result in edge damage. Special attention needs to be taken to prevent edge damage. Scraping, twisting and forceful as well as using on hard or very dense foods can result in chipping.

We recommend hand sharpening on whetstones. We have found that most Japanese knives perform best at a finer finish starting around 4000. Avoid pull through sharpeners and non-water cooled mechanized sharpening. Ceramic honing rods are preferred.