There are six major Japanese beverage firms (Kirin, Asahi, Suntory, Sapporo, Calpis, Itoen) distributing the largest part of all drinks available in vending machines or supermarkets. Among foreign companies, Coca-Cola and Nestle are well implanted on the Japanese market.
Most foreign companies who want to enter the Japanese market should pass by one of the 6 big Japanese companies, except Coca-Cola which has its own distribution network. For instance, amomg famous French waters available on the Japanese market, Evian is distributed by Calpis, Vittel by Suntory, and Volvic by Kirin.
Here is an overview of the 5 market leaders and the drinks they produce and ditribute :
Kirin : Kirin beer, distributes a vast number of foreign alcohols (wines, brandies, liquors, spirits, whiskies, Chinese & Korean alcohol) as well as Volvic.
Nestle : Nescafe, Nestea, Vittel, Perrier, Contrex, San Pellegrino...
Note the existence of Itochu, which is a zaibatsu involved not only in food & beverages, but also this zaibatsu does textiles, machinery, aerospace, electronics, multimedia, energy, metals, chemicals, finance, realty and insurance. They own Japan Bevrages and several other smaller companies.
