Ichishima is produced by Oumon Shuzo in Shibata City, Niigata, a brewery founded in 1790 by a branch of the Ichishima family, one of the region's most prominent agricultural clans. Soft water drawn from the Kaji River, which flows from the Iide mountain range, and locally grown Niigata rice including Gohyakumangoku and Koshitanrei give the sake its characteristically gentle and mellow character. The brewery also pioneered the employment of female brewery workers at a time when such practice was rare across Japan.
