The Harbour Report ranked the manufacturing plant -- which produced the first automatic transmission outside Japan -- the most productive engine plant in the United States from 2004 to 2011.
"It turned out our workforce was ideal for them because they were, and still are, hardworking," Rockefeller said. "They have always been happy with our workforce, and so that sounds promising to me."
The Putnam County plant announced its seventh expansion in March 2012. The company will spend $45 million to add 80 jobs and increase its production of six-speed automatic transmissions from about 400,000 to 520,000.
Toyota has invested more than $1.2 billion in West Virginia since 1996, making it the largest industrial investment in West Virginia in the last 50 years, according to the senator.
Rockefeller, who drives a Toyota Sequoia, said the Buffalo plant has been a huge economic engine for the state. More than 20 other Japanese companies have opened businesses in West Virginia since Toyota started making engines, he said.
"We had no idea it was going to expand and expand," Rockefeller said. "This is one of the biggest diversifications that has ever happened here because we didn't make cars before.
"If Toyota puts a plant in your state, you're a good state because it's like a stamp of approval."
Receiving a stamp of approval from the Japanese businessmen took time, Rockefeller said.
To do "something really major" in West Virginia like he set out to do, Rockefeller had to travel on numerous trade missions to Japan and encourage the Japanese to take mission trips to the U.S.
While every American state in the 1980s had commercial offices in Tokyo, Rockefeller chose Nagoya. As the first state to locate there, West Virginia got free office space in return, he said.
He ate at the oldest restaurant in Nagoya -- at least 800 years old, he guessed -- to form the necessary relationships to sell West Virginia to the Japanese company.
It's all part of the deal, he said.
"You fold yourself into their tradition and ways," Rockefeller recalled, "I sort of knew we were getting into a long-haul, 10-year project then.
"The Japanese are very shrewd in that they hold their cards very close to their vest and are always polite. You constantly work to show how much you want them there and that's why the time I spent there was very important."
As for Toyota's 18 years of successful business in West Virginia?
"I loved the process of it all. And it's not politics or campaign contributions -- it's cold, hard analysis on the part of a major Japanese company to think 'What is it going to be like to do business in West Virginia?' and it turns out they really like what they got."
Reach Megan Workman at megan.work...@wvgazette.com or 304-348-5113.