Diatomaceous earth, the material used for shichirin, is heat-resistant, allowing for charcoal firing, but it is not very durable. The highly resistant Mikawa clay, mined in the city of Hekinan, Aichi Prefecture, was used for shichirin, and shichirin production in this region became active.

The Mikawa Grill is a black, double-layered shichirin, but today, shichirin production has evolved over time to focus more on ease of use and appearance. The easy-to-use rectangular shape, the variety of colors, and the iron plate surrounding the exterior make cleaning easier. Shichirin is called Konro in this region, but the performance and products are the same as those of shichirin.

Each Konro comes with 1.5 kg of Binchotan