Crafted by skilled hands at Masumi’s two breweries in the Suwa region of Nagano Prefecture. Local rice and pure mountain water combined with the best brewing traditions and techniques. The brewery was firmly established by 1662 and had done well enough to gain the praise of several historical figures. It is said that Matsudaira Tadateru, sixth son of the first Tokugawa Shogun and part-time resident of Suwa, was so fond of their sake that he always kept it by his side. And Otaka Gengo, one of Japan’s famous 47 ronin warriors, praised its smooth taste.
They began using the name “Masumi” for their sake at the end of the Edo period (1603-1867). Masumi, which means transparency or truth, is the name of a 8th century bronze mirror kept at the Suwa Taisha shinto shrine. Their family had provided the shrine with sake for centuries, so it was only fitting that their sake took the name of the shrine’s “Masumi Mirror.” Masmi brewery struggled for a long period to keep up their business but they worked hard to "make the best Sake in Japan" in the end, this brewery not only holds a distinguished award-winning history at Sake fairs, but Masumi achieved even greater prominence in 1946 when brewmaster Kubota, discovering a lovely aroma emanating from one of the brewery's fermentation tanks, requested that an expert from the National Research Institute of Brewing be called in for consultation. Samples were taken and it was soon confirmed that a new yeast variety, Association No. 7, had been discovered. In the sake world, discovering a new yeast is like receiving the NobelPrize, and only a handful of breweries enjoy this distinction. With its gentle, pleasing aroma and ease of use, No. 7 soon spread beyond Nagano Prefecture, and today continues to be used by over half of the breweries in Japan. In 2002, Masumi released a redolent, old-style sake with an insouciant 21st-century attitude called "Nanago" (No. 7) in tribute to the famous microorganism to whom the sake world owes so much.