Inaba Shuzo was founded in 1867 at the foot of Mount Tsukuba in Ibaraki Prefecture, where spring water that percolates through the mountain feeds directly into the brewing wells on the property. The brewery is Ibaraki's first to be run by a female toji, with sixth-generation brewmaster Nobuko Inaba combining traditional techniques with formal training in fermentation science to produce sake for the Tsukubasan Shrine's sacred offerings. Minanogawa, named for the stream between the mountain's two peaks that appears in the Ogura Hyakunin Isshu poetry anthology, is pressed exclusively by bag-hanging and bottled without filtration, preserving the full character of each fermentation tank.