Imo syochu is made from sweet potatoes in Kagoshima Prefecture, the southernmost prefecture in mainland Japan. Kagoshima Prefecture is also known as Satsuma, and sweet potato is such a deeply rooted crop in Kagoshima that the name of the place is the name of the crop.
Since Kagoshima's hot climate is not conducive to sake production, imo shochu, which uses the local culture, has become popular and is produced in many parts of the prefecture.
Sake and shochu are two of the most popular alcoholic beverages in Japan, but while sake is made by pressing, like wine, shochu is made by distillation, like whisky, brandy and gin.
Until about 2000, imo shochu was only drunk in certain regions, such as Kagoshima, but with the improvement in the quality of the liquor, it is now drunk in all parts of Japan.