something you receive from a friend or family member or a friend's friend or family member
I think I see it in the supermarket sometimes. Maybe it is an easy-to-obtain sake.
In early September, it was purchased for 913 yen (excluding tax) for 300 ml at a store in front of Kurobe-Unazuki Onsen station.
A square of the bottle was also purchased at the same place for 308 yen (excluding tax).