Japanese Man Arrested in Record-Breaking Illegal Online Gambling Case

A 38-year-old Tokyo resident could be sentenced to up to 5 years in prison for online gambling after allegedly spending $194 million on the activity, which is illegal in Japan.

Man Arrested for Record-Breaking Sum Spent on Online Gambling

Makoto Chomabayashi has allegedly wagered approximately 90 million yen (around $625,500) between August 2022 and April 2025, mainly on baccarat, on the global casino site Stake, according to Japanese news outlet The Asahi Shimbun. Stake, operated by Medium Rare N.V., is licensed in Curaçao, an island nation located off the coast of Venezuela.

Chomabayashi is also accused of serving as a “casino affiliate,” promoting Stake in return for a 2% share of the wagers made by his followers. According to police, he referred over 100 individuals to the online casino, earning approximately $48,000 in commissions. The Tokyo Metropolitan Police Department reports that Chomabayashi admitted he was aware that online gambling is illegal in Japan but believed he wouldn’t be caught. Despite this, he frequently posted his winnings on X (formerly Twitter) under the alias “Meikyoshisui,” a Japanese phrase meaning “clear mirror, still water.”

According to investigators believe his involvement goes far beyond that. It is suspected that Chomabayashi placed bets totaling 28 billion yen (about $194 million). If that is the case, then this would be the largest amount ever linked to a single person in an illegal gambling case in Japan.

What’s Gambling’s Legal Status in Japan?

Japan enforces strict bans on most types of gambling, allowing only government-regulated activities such as horse racing, lotteries, and certain sports. While the 2018 Integrated Resort (IR) Act legalized casino resorts under tight regulation, online gambling remains illegal, except for limited cases like public sports pools.

However, while online gambling is prohibited in Japan, a recent survey by the National Police Agency estimates that around 3.37 million people in Japan have used online casinos, with annual wagers totaling 1.24 trillion yen (roughly $8 billion). Notably, 40% of users were unaware that their gambling activities were illegal under Japanese law.

In response, the government has updated its approach to illegal gambling, implementing tighter regulations aimed at affiliate marketers and third-party payment processors. For example, earlier this month, Japanese politicians presented a bill for stricter online gambling regulations. 

It should also be noted that online gambling seems to be rising in popularity in Japan, despite it being illegal. The National Police Agency reported 279 arrests related to online casino gambling in 2024, which is a 160% increase compared to 2023.