The main body is made of full-tanned leather tanned with vegetable tannins, which is soaked with plenty of dye and oil, and then heated with an iron to create a smooth surface with a natural luster. Because it contains a large amount of oil, it feels good to the touch and has a moist texture. Included are 3.0mm and 2.5mm thick leathers that have been tested for hazardous substances (JES) according to the 13 standards of the Japan Leather Technology Association, and are tanned with vegetable tannin without using any hexavalent chromium, a substance that is harmful to the human body. We use eco-nume cow leather. This series combines leathers with different textures and has a simple finish.