Isawa Town in Fuefuki City, Yamanashi Prefecture, located in the eastern part of the Kofu Basin, is a representative fruit-growing area in the prefecture. The water deposited by the Fuefuki River, originating from the Chichibu mountain range, on well-drained sandy and gravelly soil, and the warm climate during the growing season, nurture Isawa's Koshu grapes, which have a high ripeness, soft richness, and sweetness, resulting in a fragrant taste. Mars Wine, well-versed in Isawa's natural environment, has created a sweet Koshu wine with a delicate and rich flavor that expresses the characteristics of its Koshu grapes through the optimal brewing method. At Mars Wine, the Cryoextraction of freezing grape berries and the Cryo-maceration of freezing grape juice are used in combination as the optimal brewing method for fermenting Isawa-grown grapes.