A pure rice sake made entirely from Yamada Nishiki from Hyogo Prefecture, which reigns as the top rice suitable for sake brewing. This is Kido Izumi Sake Brewery's signature aged sake product, which has been carefully aged for over 30 years. This is an aged sake that is blended by the brewer himself from several types of unprocessed sake to achieve a balanced flavor that can be enjoyed with all five senses.

The person who named it in ancient and modern times was the late Mr. Irie Aimasa, who served as the Chief Chamberlain of Emperor Showa and had a deep knowledge of food. It is a venerable sake that, when Kokin had not yet been given a name, was so impressed by its taste that he named it himself and even wrote the words ``Kokin'' on the label.