SANTA ANA, California — As an interpreter, Ippei Mizuhara was supposed to bridge the gap between baseball star Shohei Ohtani and his English-speaking teammates and fans, as the duo traveled from Southern California to ballparks across the United States.

Instead, Mizuhara exploited the Japanese-English language barrier to isolate Ohtani and profit, in the truest sense, from his proximity to the two-way player's power. On Tuesday, the former interpreter pleaded guilty to bank and tax fraud in federal court in Santa Ana, California, after stealing nearly $17 million from the unsuspecting athlete's Arizona bank account.

He spent the money to cover his growing gambling problem and debts with an illegal bookmaker, plus $325,000 worth of baseball cards and, to the shock of prosecutors, his own medical bills.

"In fact, after we announced the charges, we only discovered more fraud in this case," said Martin Estrada, US Attorney for the Central District of California. "We discovered Mr Mizuhara had victimized Mr Ohtani to the extent that he wouldn't even pay for dental care. He stole money from Mr Ohtani to pay for his own dental expenses."

The case involved, arguably, the world's most famous baseball player and the sport's most valuable voice. Despite the international media frenzy, Tuesday's 45-minute proceeding was fairly mundane: Ohtani was referred to as "Victim A" inside the courtroom, and the former interpreter only spoke to acknowledge his guilt.

"I worked for Victim A and had access to his bank account and had fallen into major gambling debt," Mizuhara told the judge. "I went ahead and wired money with his bank account."

He and his attorney declined to comment after the hearing.

Inside baseball, Mizuhara stood by Ohtani's side for many of the Japanese sensation's career highlights, from serving as his catcher during the Home Run Derby at the 2021 All-Star Game, to being there for his two American League MVP wins and his record-shattering $700 million, 10-year deal with the Los Angeles Dodgers.

Off the field, Mizuhara became Ohtani's friend and confidant. He famously resigned from the Los Angeles Angels during the 2021 MLB lockout so he could keep speaking to Ohtani — he was rehired after a deal was struck — and their wives reportedly socialized.

But, Mizuhara gambled it all away, betting tens of millions of dollars that weren't his to wager on international soccer, the NBA, the NFL and college football — though prosecutors said he never bet on baseball.

Estrada, the US attorney, said Ohtani was particularly vulnerable, despite his fame.

"Mr Ohtani is an immigrant who came to this country, is not familiar with the ways of this country, and, therefore, was easy prey to someone who was more familiar with our financial systems," Estrada said during a news conference in downtown Los Angeles after the hearing.

Federal prosecutors said Mizuhara's scheme began in 2021, when he switched the bank account's contact information from Ohtani's to his own, meaning any communication from the financial institution would be sent directly to him without Ohtani knowing.

Mizuhara capitalized on the language barrier to keep Ohtani's financial advisers from understanding their client, and at times, Mizuhara even impersonated the player to the bank to prolong the fraud.

The ploy allowed Mizuhara to plunder just under $17 million from the account — which he'd helped Ohtani set up in Phoenix in 2018 to deposit his paychecks — from 2021 until earlier this year.

Mizuhara's winning wagers totaled over $142 million, which he deposited in his own bank account and not Ohtani's. But, his losing bets were around $183 million, a net loss of nearly $41 million.

Tuesday's guilty plea was anticipated after Mizuhara agreed to a deal with the US Attorney's Office last month.

He pleaded guilty to one count of bank fraud, which carries up to 30 years in federal prison, and one count of subscribing to a false tax return, which could add a maximum of three years of incarceration.

A sentencing hearing is scheduled for October. Mizuhara also could be on the hook for restitution to Ohtani that could total nearly $17 million, as well as more than $1 million to the IRS. And, as a legal permanent resident who has a green card, he might be deported to Japan.

The investigation into Mizuhara stemmed from a broader probe of illegal sports bookmaking organizations in Southern California and the laundering of proceeds through casinos in Las Vegas. Overall, authorities have netted a dozen defendants.

There was no evidence Ohtani was involved in, or aware of, Mizuhara's gambling, and the player cooperated with investigators. He expressed relief after Tuesday's hearing and, in a statement, thanked his team, his family and the Dodgers organization "who showed endless support throughout the process."

Agencies via Xinhua