The liquor store where I bought it said it was called "Komatsubito". It has a faint sweetness and acidity. The acidity is impressive. It's a type of sake that may be common, but there is no other type of sake. It's hard to explain but it's an interesting sake. I heard there are not many places where it is sold.
I bought it at a liquor store in Kobe, but the owner of the store requested the brewery to make a 4-gourd bottle of Komatsujin, which was previously only available in 1-shochu bottles.