OSAKA, Japan -- It may have just been an exhibition game, but on Monday night when Team Japan faced the Hanshin Tigers before the World Baseball Classic begins in full, history was made. That's because batting first and playing left field was Lars Nootbaar, the first player to suit up for the Japanese national team who wasn't born in Japan.

The big moment started with a little confusion, though.

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"We were wearing our home unis, so I thought we were home," Nootbaar said after the game, his eye black fading but a wide smile still etched on his face. "I was getting ready to go out on defense, but they were like, 'Oh no, you’re going out there [to hit].' I was like 'Oh shoot.' I got sped up a little bit, but it’s probably good. I didn’t have to think about it all day."

A few pitches later and it all worked out: In his first at-bat, Nootbaar laced a single and celebrated with the Cardinals' pepper-grinder celebration. That started a Team Japan tradition, too -- a visual cue that would connect Nootbaar with his new teammates.

"We wanted a little hit celebration, something to do," Nootbaar said. "We didn't really know what to come up with. And so [Shohei Ohtani] said, whatever I go out there and do first, that's what we're gonna roll with. So, I went out [and got a hit] in the first inning, we got the pepper grinder out there. We stuck with it."

Two innings later, Ohtani hit a home run and, sure enough, made sure to grind some pepper as he rounded third base. It was the clearest sign that this team had accepted their new teammate into the fold.

"Even those nurtured in different countries' baseball can connect on a person-to-person level," manager Hideki Kuriyama said when Nootbaar was announced on the roster in January. "They can be companions."

"I think that is one of the strengths of sports, the ability to go beyond nationality. I told him this is a big first step for Japanese baseball."

Though Nootbaar's inclusion on the roster is a first, it's actually something that's been in the works for his entire life. His mother is from Saitama, and the Cardinals outfielder became enamored with Team Japan when he was just a young boy. His family played host to players from a traveling high school All-Star team, which featured future Yankees star Masahiro Tanaka. Just 9 years old, Nootbaar was welcomed into the fold like he was one of them. He would join the team on the field for pregame stretches before taking on batboy duties for the rest of the game.

"They were my role models, they were like pros even though they were just high schoolers," Nootbaar said. "My family accepted them as their kids, and for me, it was like having a brother for a couple weeks. It’s nice that it’s the opposite now."

When Team Japan's roster was announced, some of those players even called his family to offer their congratulations.

"They were just super excited. They were super pumped. They couldn’t believe that the little batboy from 10-15 years ago is now playing and representing Team Japan. They were all super excited, and I’ve been welcomed with open arms. It’s been a really cool experience for me, I couldn’t ask for anything better."

That experience has been mirrored by his new teammates, too. Born with the Japanese name of Tatsuji in honor of his grandfather -- he, along with the rest of his mother's side of the family still lives in Japan -- has earned Nootbaar the nickname "Tachan." When the Cardinals outfielder arrived to Team Japan's camp, all the players were wearing special T-shirts with his nickname and flags from both countries printed on the back.

"Obviously, my mom is very proud," Nootbaar said. "That’s very cool because I’m a mama's boy and she’s my best friend. She’s sacrificed so much for me, so to do something and put a smile on her face and represent her [heritage] -- it means a lot to me."

There may be a language divide between Nootbaar and his teammates, but it hasn't gotten in the way of the game or fast friendships.

"When I’m on the field, it’s completely clear. I try as much as I can to spit out main words, so they can understand and they do the same. They’re great with their English too, surprisingly," Nootbaar said. "What do they say? Ninety percent of communication is nonverbal anyway, so I think they get my vibe, I get their vibe. It’s pretty cool."

Nootbaar will have plenty of family members on hand at the Tokyo games, eager to see their California-born relative suit up in Japan's traditional pinstriped uniform. He'll even have a new skill to show off: He's learned the lyrics to "Kimigayo," the Japanese national anthem.

"I was actually next to the manager today and we were singing it together," Nootbaar said. "I was singing it just to prove that I knew some of the words. That was pretty fun."