Sanraku Ocean has a complex history rooted in multiple corporate mergers, primarily involving two companies: Sanraku and Ocean. Sanraku was originally established as Showa Shuzo in 1934 and renamed Sanraku Shuzo in 1949. The company operated two whisky distilleries: Karuizawa (established in 1958) and Yamanashi (established in 1961). Following the 1962 merger that created Sanraku Ocean, Karuizawa became the group's primary malt whisky distillery, while Yamanashi ceased whisky production in 1965. Yamanashi briefly resumed distillation from 1967 to 1969 before permanently closing its whisky operations to focus exclusively on wine production.