Kumamotoken Shuzokenkyusho is both a prefectural research center and a brewery that makes the Koro sake brand. It was founded in 1909 when they were shifting from making the locally familiar red sake to making “seishu” (clear sake). In 1952, the researcher and founder Mr. Nojiro isolated Koro yeast (aka. Kumamoto yeast), which is distributed as Association No. 9 yeast by the Brewing Society of Japan and widely used as a reliable fermenter today. Their head of production oversees the research and brewing, contributing to raising the quality of sake making in Kumamoto prefecture.