A characteristic of traditional Japanese knives is that they are single-edged knives.

Basically, it is a two-layer structure with soft iron, called Jigane, on the front and hard steel on the back.

Its back side has an indentation, called Urasuki, which reduces the surface in contact with the food.

Therefore, the blade can be easily sharpened by simply placing it on the whetstone without maintaining an angle.

This temptation is so great that even professional cooks are tempted to over-sharpen their backsides.

As a result, Urasuki is lost and the original quality of the Japanese knife is compromised.

The backside should not be sharpened too much and rust should also be taken care of.

The planes leading to the edge called Kireha, which is sharpened with a whetstone, can be cleaned by sharpening and the front surface, called Hira, is soft iron and easy to remove rust.

But the backside is hollow and hard steel, so it is not easy to remove rust.

Please take extra care in taking care of it.