Parra, 32, agreed to a deal Wednesday with the Yomiuri Giants of Nippon Professional Baseball. The veteran outfielder energized the Nationals this postseason, using his Baby Shark walk-up song to spark the team to its first World Series in franchise history.
"I am proud to be a member of the Yomiuri Giant Army with history and tradition," Parra said in a news release. "Playing at a high level of professional baseball in Japan is an opportunity to improve my ability.
"I'm going to devote all of my experience and knowledge to the Giant Army, and for the fans, always try to play energetically for the team and contribute to the team's victory."
Parra joined the Nationals in May after being designated for assignment by the San Francisco Giants. He hit .250 with eight home runs and 42 RBIs in 89 games for the Nationals.
He hit .284 with six homers and 53 RBIs in 142 games for the Colorado Rockies during his 2018 campaign. The two-time Gold Glove winner and 2013 Overall Defensive Player of the Year award winner has a career .276 average with 88 home runs in 11 seasons in Major League Baseball.
Parra appeared in games for the Arizona Diamondbacks, Milwaukee Brewers and Baltimore Orioles before his time with the Rockies, Giants and Nationals. He made his MLB debut in 2009 with the Diamondbacks.