Masakage Koishi knives are handmade with carbon steel clad with stainless steel. This is a great way to make a knife as you get all the performance of carbon steel (a very long lived edge, ease of sharpening and a silkiness when cutting) without most of the maintenance issues as cladding with stainless steel reduces the risk of rusting.

Aogami Super carbon steel clad with stainless steel
Rockwell Hardness 63:65
Octagonal handle of American cherry and pakka ferrule.

"Making knives is delicate work with many considerations." - Hiroshi Kato, Master Blacksmith, father and teacher of Master Blacksmith Yoshimi Kato, maker of Koishi knives.

The best sharpening tools for Japanese knives are leather strops and fine whetstones.

Japanese chef knives are brittle and are designed for cutting soft tissue foods. High Carbon steel chef knives can rust if not kept dry.