Founded in 1804 by Kanpei Tsuneshichi in Itako, Ibaraki Prefecture, Aiyu Shuzo has brewed sake for over 220 years in a town historically known for its canals and water transportation routes. The name Aiyu (愛友) means loving friends, rooted in the founder's spirit that all people in the world are like brothers. The brewery selects rice from Itako and various regions across Japan to match each style, producing a range from dry to sweet with particular focus on ginjo-grade offerings and seasonal limited editions.