Two-way ace Ohtani - one of the biggest names in baseball - will pitch in Japan for the first time since he joined the Los Angeles Angels in Major League Baseball in 2018 when he takes to the mound against China on Thursday.
Ohtani is an icon in baseball-loving Japan and his presence in the national team has stoked expectations that they can win the global tournament for a record third time.
All eyes were on him as he spoke to reporters at Tokyo Dome, where Japan will play all their first-round games and a potential quarter-final.
"I'm really excited - it's the first game and I want to go into it with the highest concentration," said Ohtani, who hit two huge home runs in a warm-up game earlier this week.
"It's my first World Baseball Classic so I will be nervous, but I want to play the way I usually do and prepare the way I usually do."
Ohtani has earned comparisons with the legendary Babe Ruth for playing as both a pitcher and a hitter - something almost unheard of in baseball.
He has enjoyed huge success since moving to MLB and was named American League Most Valuable Player in 2021.
Ohtani said he was not sure if he would be up to full speed when he makes his first pitching start of the year against China but promised to "give 100 per cent".
"I probably won't pay too much attention to how many pitches I've had," he said.
"All I'll be doing is focusing on each batter and each pitch."
Freak of nature
Japan has assembled a star-studded team for the World Baseball Classic, combining the best of the country's domestic league with MLB-based players like Ohtani and Yu Darvish (36) of the San Diego Padres.
Manager Hideki Kuriyama has also called up American-born St Louis Cardinals player Lars Nootbaar (25), who has a Japanese mother.
Nootbaar said Ohtani was "a freak of nature" who he was enjoying watching up close.
"I'm just like you guys - I'm just a fan being able to watch him. I just, fortunately, get a front-row seat," said Nootbaar.
"It's been pretty amazing to watch him go about his business and handle himself on and off the field. It's really impressive."
Japan won the inaugural World Baseball Classic title in 2006 and defended their crown three years later.
This year's competition, which is also being held in Taiwan and the United States, was postponed from 2021 because of the coronavirus pandemic.