California rice farmer Charley Matthews Jr. remembers the excitement when Japan first started buying rice from the United States in 1993.

"It really helped rice prices here," Matthews, chairman of the California Rice Commission, said. It was also the beginning of a learning experience for California growers. Until then, marketing rice was not about quality, "it was about how many sacks you could grow," he said.

With 20 years of experience growing rice for Japan, California producers are hopeful the Trans-Pacific Partnership will open the market even more. Japanese negotiators are joining the latest round of TPP talks being held through July 25 in Malaysia.