Vintage Japanese Enamel Sign. “Mitsuuroko Good Quality Charcoal” Neon Beer Cocktail Bar Retro. Cool Vintage Japanese Enamel Sign. = Mitsuuroko (Company Name). = Tochigi Sanraku Co. Please check out my other auctions for more Japanese vintage, retro, industrial and antique bits. Mitsuuroko was founded in 1886 (Meiji 19) when Tatsusaku Tajima opened Kaneichi Transport Store in front of Shinmachi Station on the Takasaki Line before being established in 1919 (Taisho 8) as Mitsuuroko Coal Co. Currently Mitsuuroko Business Co. Mitsuuroko produces Rentan charcoal which is made by molding powder such as coal, coke, and charcoal into a cylindrical shape with lotus root-shaped holes together with a binder. Used for household, commercial and industrial use. Household wrought charcoal generally refers to No. 4 size wrought charcoal, which is molded into a cylindrical shape and has about a dozen holes that allow air to pass from the bottom surface to the combustion surface.