Ofukumasamune, brewed by Ofuku Shuzo in Nagaoka City, Niigata Prefecture since 1897, carries a historic distinction: its founder Kishigoro developed the sokujyo-moto rapid-starter method that is now standard practice in breweries across Japan. Drawing on contract-cultivated rice and the brewery's proprietary soft water, the sake is aged with minimal carbon filtration to preserve the gentle sweetness and rounded umami that define its unchanging house style.