On the twenty-second of January 2021, the sake of Tonenumata was designated a geographical indication. It was the sixth such designation for sake, after Hakusan, Yamagata, Nada Gogo, Harima, and Mie.

Tonenumata sits at the northern edge of Gunma, hemmed in by mountains: the Mikuni range with Mount Hotaka and Tanigawa to the north, and the volcanoes of Nikko-Shirane, Akagi, and Asama to the south.

The standards are narrow. The rice must be Yukihotaka, Gohyakumangoku, or Koshihikari, and it must have been grown inside the district. Only certain yeasts are permitted, and the fruit-like aromas the region claims for its sake are attributed to them: grapefruit, white peach, yellow apple, banana, melon, lychee.

The part that stays with me is the water. Rain falling on Hotaka and Tanigawa works down through beds of sand and silt laid on the floor of a lake that used to be here, the old Numata lake, and comes out soft. That is what the producers credit for the clarity of the sake, in flavor and in color. The lakebed is around a hundred and fifty thousand years old. It is still doing something, every winter, to what goes into the bottle, and the sake it produces is described as clear on the palate with a measured savor behind the acidity.