Oyama is located in the heart of nature in Miyazaki Prefecture. Founded in 1930, it relocated to the city of Aya in 1973 to be closer to the purest water source needed to make its vinegars. Aya's renowned water has been purified by the dense forest that surrounds it. Oyama's products are organic, pesticide-free products made from pure water, brown rice and koji according to a simple traditional process where the southern sun and the action of time are key elements.