Danone announced it had bought the 50 per cent stake in Calpis Ajinomoto Danone (CAD) it did not already own, as part of its expansion strategy in Asia.
Asia has become a hive of activity for some of the world's largest dairy firms as they look to take advantage of emerging markets there.
Danone said its latest move in the region would enable it to better focus on products and brands that carry distinct health benefits.
"Japan is a priority market for Danone in Asia and the success of our product BIO in Japan illustrates there is room for growth of products that deliver distinct health benefits," said Emmanuel Faber, executive vice president of the firm's Asia Pacific division.
Japan is well-known for its place at the forefront of functional food categories, and the country has a strong reputation for innovative products in this area.
This, combined with low per capita dairy consumption, makes Danone confident about the country's potential.
The French firm has worked with Ajinomoto in Japan for 27 years and Calpis for 14, helping it to establish the Danone brand in various categories.
Ajinomoto will continue to be the sole distributor of Danone's fresh dairy in Japan, while Calpis will continue to supply raw materials for the products.