How water makes Sake different?

Obviously water plays a big role in Sake. It consists of 80% water and 20% rice, rice koji, yeast and alcohol etc. During its brewing process, water is added more than fifty times the total weight of the rice. Therefore it's said that water affects Sake's quality. What is suitable water for Sake production? Water is transparent but contains many elements. Among them potassium, phosphoric acid and magnesium are necessary for Sake production because they help yeast propagate and koji mold develop in a good quality. There are other elements in water which impact Sake's quality negatively such as iron and manganese. Iron darkens the sake and impacts both flavor and aroma. Manganese occurs a chemical reaction when it's exposed to light and it causes bad color and dulls the appearance of Sake.
In Japan there are three famous water sources: Miyamizu in Hyogo (near Osaka), Gokusui from Kyoto and Fukuryusui from Mt.Fuji.
How are they different?
Miyamizu contains sufficient phosphorus and potassium while it has little iron. Water in Japan is considered to be soft water but Miyamizu is harder thanks to high mineral contamination. Sake from Miyamizu tends to be dry and rough.
Gokusui, on the other hands, is softer and sweeter and Sake from it tends to be mild and sweet. Compared with Sake from Miyamizu it's called 'Feminine Sake' while one from Miyamizu is called 'Masculine Sake'. Gokusui also has an interesting history. It was discovered inside the shrine compounds during the Heian period and got popular immediately because of its aroma. Gokusui means 'honorable aromatic water' and is one of the highest ranking among Japan's 100 best waters.
Fukuryusui comes from Mt.Fuji which was soaked into the deep volcanic soils for many years. It has well-balanced calcium and magnesium, the ratio of 3:1 and realises the most suitable taste for Japanese palates. It must be interesting to compare Sake from each region so that you can find your best one ;)