Meet the man who changed American baseball for the Japanese forever.

On September 1, 1964, Masanori "Mashi" Murakami came in as a relief pitcher for the San Francisco Giants against the Mets in New York.

Though the Giants ended up losing 4-1, he allowed no runs in his debut, and to boot, he became the first ever Japanese man to play in Major League Baseball.

Murakami in his Giants uniform. Photo by National Baseball Hall of Fame Library, Cooperstown, New York. Used with permission.

Murakami had been a baseball prodigy in Japan, playing in the Nippon Professional Baseball league while he was still in high school.

He made his Japanese pro debut in 1962 for the Osaka-based Nankai Hawks, when he was only 19 years old. According to the History Channel, Murakami threw his pitches with a sidearm delivery, a deceptive style that was then common in Japan but less so in the United States.

The Giants heard about Murakami through Tsuneo "Cappy" Harada, an American businessman who had been living in Japan (and apparently earning himself a great nickname). Harada had been scouting Japanese players for the Giants, according to the Baseball Hall of Fame blog, and Murakami stood out as exceptionally talented.

Throwing out the first pitch during a game at the Tokyo Dome in 2014. Photo by Atsushi Tomura/Getty Images.

In 1964, as a part of an exchange program, he left his home country and headed to Arizona, where he would participate in spring training with a Giants-affiliated minor league team.

Within the same year, a then-20-year-old Murakami found himself pitching in front of a crowd of about 40,000 people at Shea Stadium in his MLB debut against the Mets.

"I go to the fence and the door opens, and I go in," Murakami recently told The Guardian. "I'm walking to the mound, that time, wow. But [being] inside [the field] is very different. Maybe if I get nervous, it's not good. Now, I think OK, make me relax. The stands, the people. I can hear, but I don't know what they're saying. I understood a little English."

Murakami shakes hands with Chicago Cubs pitcher Tsuyoshi Wada at the Tokyo Dome in 2014. Photo by Atsushi Tomura/Getty Images.

Murakami, it seems, wasn't trying to make it big or be a hero.

"I was never thinking of the major leagues," he said in July. "I just wanted to pitch."

His impact on American baseball was long-lasting, even if his playing career was not.

Murakami was a relief pitcher with the Giants for the rest of the 1964 season and continued into the next year, but he only appeared in 54 games during that span. After a contract dispute between the Giants and the Nankai Hawks, he went back to play in Japan until the early-1980s.

Though he is now sometimes referred to as the "Jackie Robinson of Japanese baseball," his historic achievement did not immediately become a watershed moment.

Signing autographs before a July 1995 legends game at The Ballpark (now Globe Life Park) in Arlington, Texas. Photo by Paul Buck/AFP/Getty Images.

Robert K. Fitts, who wrote "Mashi: The Unfulfilled Baseball Dreams of Masanori Murakami, the First Japanese Major Leaguer," told Boston-based WBUR that Murakami's quick exit from the MLB was more about contractual obligations than his ability on the field.

"After Mashi returned to Japan, Major League Baseball and Japan Professional Baseball came to an agreement that each side would respect the reserve clauses of the other country's contracts," Fitts told WBUR in August. "Now back then there was no free agency, players were tied to their teams until they retired or were traded. So, in effect, that agreement kept all Japanese players in Japan."

Murakami being honored before a 1995 game in San Francisco. Photo by John G. Mabanglo/AFP/Getty Images.

There were no other Japanese players in Major League Baseball until Hideo Nomo played for the Los Angeles Dodgers in 1995.

That helped create a pathway to the U.S. for more Japanese players, such as Ichiro Suzuki, a right fielder who still plays today and has already racked up numerous MLB awards, and Hiroki Kuroda, a pitcher who spent seven seasons with the Dodgers and New York Yankees.

Pitcher Hideo Nomo became the second Japanese-born MLB player in history when he debuted against the San Francisco Giants on May 2, 1995. Monica M. Davey/AFP/Getty Images.

There's still lots of room for growth. Asians only made up 1.9% of the Major League players in 2012, according to data compiled by the Society of American Baseball Statistics.

Regardless, Murakami will be remembered as a trailblazer. "For a long time, he was kind of a footnote in history. He was a trivia-question answer," Fitts told TIME Magazine. “But he was a true hero."

Even though Murakami's achievement did not immediately lead to more Japanese players in the majors, he showed they could play ball — which continues today.