"Kairagi" is the skin of fish with hard protrusions from rays and sharks, and during the Sengoku and Edo periods, the skin was polished and used to decorate the sheaths and hilts of swords. By polishing this fish skin, a pattern resembling the petals of a plum blossom appeared, and it was called ``Kairagi'' (plum flower skin).

The surface of ``Kairagi'' resembles plum blossom skin because of the atmosphere of the kiln, the particle size distribution of the soil, and the glaze composition. When firing the glaze, a phenomenon called "crinkle" occurs, and this crinkle forms a beautiful pattern. In particular, the presence of water vapor became an important point, giving rise to the unique patterns of plum blossom skin, which were valued for their beauty.