Shohei Ohtani, Ippei Mizuhara, and Gambling in the Inner Circle

Timeline

1. 2018Mizuhara joins the Los Angeles Angels as Ohtani's interpreter, having worked with him in Japan.
2. 2021–2023According to prosecutors, Mizuhara runs up large debts to an illegal bookmaking operation and begins moving money from Ohtani's account.
3. Mar 20, 2024Ohtani's attorneys accuse Mizuhara of "massive theft"; the Dodgers fire him.
4. Mar 25, 2024Ohtani publicly says he never bet on sports or knowingly paid a bookmaker.
5. Apr 11, 2024Federal prosecutors charge Mizuhara with bank fraud, saying he stole more than $16 million by impersonating Ohtani.
6. Jun 4, 2024Mizuhara pleads guilty to bank fraud and subscribing to a false tax return.
7. Feb 6, 2025Mizuhara is sentenced to 57 months in prison and ordered to repay nearly $17 million to Ohtani and more than $1 million to the IRS.

The ethical issues

• Trust and dependence: a non-English-speaking star relied on one person for language, finances, and daily life.
• Duties of support staff: interpreters and aides are often outside league rules and education programs.
• Presumption of innocence vs. public suspicion: early inconsistent accounts led to speculation about the star himself.
• Gambling addiction: the role of illegal bookmaking and a disorder that drove the theft.
• League self-interest: MLB's incentive to protect its biggest star while investigating.

Stakeholders

Stakeholder	Interests & obligations
Shohei Ohtani	His finances, reputation, and eligibility; his trust in his closest aide.
Ippei Mizuhara	Criminal liability; his gambling disorder.
Dodgers and Angels	Duties to supervise staff around players; reputation.
MLB	Integrity of the game; credibility of its investigation of a marquee player.
Illegal bookmakers and federal prosecutors	Prosecution of illegal gambling operations.
Other players with interpreters or entourages	Safeguards against similar exploitation.

The case

When Shohei Ohtani arrived in Major League Baseball in 2018, he brought a constant companion: Ippei Mizuhara, who had worked as an interpreter for Ohtani’s Japanese team. Mizuhara translated in clubhouses and press conferences, drove Ohtani, played catch with him, and became his closest aide. He was a familiar face to fans; he even caught for Ohtani in the 2021 Home Run Derby.^[1][5]

That closeness turned out to be the danger. On March 20, 2024, during the Dodgers’ season-opening trip to Seoul, Ohtani’s lawyers said he had been the victim of “massive theft.” The Dodgers fired Mizuhara.^[3] The story had shifted within a day. In an interview with ESPN, Mizuhara had initially said Ohtani paid his gambling debts to help him, before Ohtani’s representatives disputed that account and alleged theft. Mizuhara then withdrew the claim.^[1][4]

Because of the shifting accounts, there was intense speculation about whether Ohtani himself had bet, or knowingly paid a bookmaker, either of which could violate MLB rules. On March 25, Ohtani read a statement saying he had never bet on sports or asked anyone to do so on his behalf, and that Mizuhara had lied to everyone.^[1]

Background

Mizuhara, born in 1984 in Tomakomai, Hokkaido, met Ohtani in 2013, when both arrived at the Hokkaido Nippon-Ham Fighters, where Mizuhara was an interpreter.^[1] The Angels hired him as Ohtani’s personal interpreter when they signed Ohtani, and he stayed in the role after Ohtani moved to the Dodgers.^[1] His job blurred into personal service. He caught Ohtani’s bullpen sessions and threw with him before games.^[1] During the 2021–22 MLB lockout, he temporarily resigned from the Angels so that he could keep working with Ohtani despite rules against contact between players and team personnel.^[1] In 2021 he told the press that he spent more time with Ohtani than with his own family.^[1]

The public story began to unravel in the clubhouse. After the March 19 game against the Padres, Mizuhara told Dodgers players he had a gambling addiction. According to the case record, he said in that meeting and in his ESPN interview that Ohtani had transferred the money to help him.^[1] That evening, Ohtani’s lawyers issued the theft statement and said the matter had been referred to authorities.^[1]

The rules and governance

The first account, in which Ohtani himself had paid an illegal bookmaker, raised immediate questions about Ohtani’s own exposure. The theft account reversed that picture.^[1] Mizuhara’s bets were not on baseball, according to prosecutors.^[1][2] The federal charges were bank fraud, based on his impersonating Ohtani in conversations with the bank, and filing a false tax return. He pleaded guilty to both on June 4, 2024.^[1]

The sentence included three years of supervised release after prison.^[1] Because of his felony conviction, Mizuhara is likely to be deported to Japan after completing his sentence.^[1] The lockout episode showed how the interpreter’s role sat outside normal team structures, making oversight harder.^[1]

The prosecution

On April 11, 2024, federal prosecutors in Los Angeles charged Mizuhara with bank fraud. They said he had gained control of a bank account into which Ohtani’s salary was deposited and had impersonated Ohtani on calls with the bank. Over time he transferred millions to an illegal bookmaking operation to cover huge losses on sports bets, though not on baseball. Prosecutors found no evidence that Ohtani knew.^[1][2]

On June 4, Mizuhara pleaded guilty to bank fraud and filing a false tax return. In February 2025, a federal judge sentenced him to 57 months in prison and ordered him to pay nearly $17 million in restitution to Ohtani and more than $1 million to the IRS. His lawyers had argued that a gambling disorder drove his conduct and asked for a lighter sentence.^[2][6]

The sentencing release set out the mechanics in detail. Mizuhara was “the translator and de facto manager” of a player identified in court papers as “Victim A,” who was in fact Ohtani. Because Ohtani’s agents and financial advisors did not speak Japanese, they dealt with him through Mizuhara. In March 2018 Mizuhara interpreted at a bank branch in Phoenix when Ohtani opened the account for his MLB salary and received the login details.^[2] Mizuhara began betting with an illegal bookmaker in September 2021 and soon fell into debt. From no later than November 2021 until March 2024, he signed into the account with Ohtani’s password and changed the registered email address and phone number, so that the bank called him, not Ohtani, to verify wire transfers. He impersonated Ohtani on about 24 calls to the bank.^[2] He also charged $60,000 of his own dental work to the account while depositing Ohtani’s check for the same amount into his own account. Between January and March 2024 he bought about $325,000 of baseball cards with the account’s money, intending to resell them. When Ohtani’s agent and advisors asked for access to the account, he told them Ohtani wanted it kept private.^[2] On his 2022 tax return he reported $136,865 in taxable income and failed to report an additional $4.1 million.^[2]

The judge ordered restitution of $16,975,010 to Ohtani and $1,149,400 to the IRS.^[2] The acting U.S. attorney said Mizuhara “had a unique position of trust that gave him power, brought him fame, and paid him well,” and that he “exploited this dream job to steal millions of dollars from his friend and confidant.”^[2]

Why it happened

The case highlighted the unusual dependence of foreign-born stars on interpreters, who often serve as translator, logistics manager, confidant, and cultural guide all at once. Mizuhara’s colleagues described him as a lifeline for players far from home.^[5] That trust gave him access that few others had, and few checks. Questions were also raised about Mizuhara’s background: reporting found that some of his earlier biographical claims, such as attending the University of California, Riverside, were inaccurate.^[4]

The arrangement also showed how the role straddled employers. Although Mizuhara was employed by the Angels and later the Dodgers, Ohtani paid him separately to drive him to meetings and interpret for activities unrelated to baseball.^[2]

Aftermath

A Dodgers staff member who had previously interpreted for pitcher Kenta Maeda took over as Ohtani’s interpreter.^[1]

The core dilemma

Elite athletes increasingly rely on entourages that manage their language, money, and lives. When a trusted aide betrays that trust because of gambling, how should responsibility be shared among the individual, the team, the league, and the athlete? And how should institutions treat a star while the facts are unknown?

Competing values

• Trust vs. oversight: close personal relationships make an athlete’s life work but create unchecked power.
• Privacy vs. scrutiny: a star’s finances are private until they become a matter of league integrity.
• Compassion vs. accountability: addiction may explain wrongdoing but does not excuse theft.
• Protecting a franchise player vs. impartial investigation: a league’s commercial interest in its biggest star.

Strongest arguments

For seeing this mainly as an individual crime: Mizuhara lied, impersonated his employer, and stole millions. Institutions cannot prevent every determined fraud, and Ohtani’s victimization was confirmed by a federal investigation.

For institutional responsibility: teams and the league knew Ohtani depended entirely on one person and did little to guard against abuse. Support staff need the same gambling education, monitoring, and separation of duties that players receive.

Applying the frameworks

Kantian (duty)

A Kantian lens condemns Mizuhara’s theft and impersonation as a profound betrayal of trust, treating his employer as a means to cover his debts. It also asks whether Mizuhara’s initial false account, which could have harmed Ohtani’s career, compounded the wrong.

Utilitarian

Consequentialists weigh the harms of gambling expansion, including addiction, debt and crime, against its benefits, and ask what controls (financial oversight, education, support for gambling problems) would reduce harm for everyone around players, not only the players themselves.

Ethics of care

The care lens notices that Mizuhara’s role combined deep dependence and isolation on both sides. It asks how teams can support interpreters and other staff who struggle, including with gambling problems, before harm occurs, while still protecting players.

Walk it through: the Simple Decision Model

1. Spot the issue. You are a team’s director of player services when you learn that a star player’s interpreter controls access to the player’s bank account. The stakeholders include the player, the interpreter, the team, the league and fans. The codes in play are MLB’s gambling rules, banking practices and team policies.
2. Gather facts. Who has authority over the player’s finances? Are there independent advisers and regular statements? Is there any sign of financial distress?
3. Test options. Options: (a) leave arrangements to the player; (b) recommend independent financial management and controls; (c) also provide gambling education and confidential support to staff. Weigh the player’s privacy and autonomy against risk.
4. Check codes and law. Are you avoiding the topic because of the player’s status or the closeness of the relationship? Would your inaction look reasonable if theft were later discovered?
5. Decide and document. Record your recommendations and the player’s response.
6. Communicate and follow up. Communicate the risks openly to the player and offer support, then review the arrangements regularly.

What’s settled and what’s contested

• Settled: Mizuhara’s guilty plea and sentence; the finding that Ohtani was a victim.
• Contested: how much oversight teams owed Ohtani; whether MLB’s investigation was sufficiently independent; the weight to give gambling disorder at sentencing.

Why this case matters

The Mizuhara case moved the integrity conversation from players to the people around them. It is a practical lesson in safeguarding entourages in the era of legal sports betting.

Key terms

Integrity

A commitment to honesty and ethical principle in competition and administration, including when nobody is watching.

Controls

Concrete safeguards that make ethics operational: training, disclosure forms, testing, monitoring, hotlines. Ethics needs principles, process and controls.

Principal–agent problem

When those acting on others’ behalf (agents such as executives, officials or agents) have interests that diverge from the people they serve.

Trust

The public’s belief that what they are watching is real. Integrity failures are ultimately failures of trust.

Definitions from the Ethics Cases glossary.

Discussion questions

1. What duties did the Angels, Dodgers, and MLB have to protect a foreign player who depended on a single interpreter?
2. Before the facts were established, many fans and commentators suspected Ohtani himself. Was that suspicion reasonable, and what does fairness require in such moments?
3. Should gambling addiction affect how we judge Mizuhara's conduct, morally or legally?
4. How should a league investigate a scandal involving its most valuable star to maintain credibility?
5. What safeguards would you require for athletes' entourages, and who should enforce them?

Sources

1. Ippei Mizuhara — Wikipedia
2. Former interpreter sentenced to nearly 5 years in prison for illegally transferring nearly $17 million from baseball player's bank account — U.S. Department of Justice, C.D. Cal.
3. Shohei Ohtani's attorneys accuse interpreter of 'massive theft' tied to alleged gambling — Los Angeles Times
4. The mysterious life — and questionable claims — of Shohei Ohtani's interpreter — Los Angeles Times
5. How interpreter Ippei Mizuhara became players' lifeline — ESPN
6. Interpreter Ippei Mizuhara sentenced to five years for defrauding Shohei Ohtani — The Athletic