Japanese citizens placed an estimated ¥6.45 trillion (€38.5 billion) in bets last year through overseas sports gambling websites, according to a new report, despite such platforms being illegal in Japan.
The report, published on 14 May 2025 by the Tokyo-based Council for Sports Ecosystem Promotion, found that the scale of the illegal market has grown rapidly in recent years. It also highlighted that roughly ¥1.02 trillion (€6.1 billion) of the total wagers were placed on domestic sporting events, including professional baseball and football.
The nonprofit organisation gathered its data from overseas research firms and licensed operators in jurisdictions where sports betting is legal. The findings come shortly after two professional baseball players were sent to prosecutors for allegedly betting on sports through foreign websites while in Japan.
Professional baseball attracted the largest share of domestic bets at ¥528.1 billion (€3.1 billion), followed by football at ¥333.4 billion (€2 billion) and basketball at ¥86.9 billion (€517 million).
Illegal bets nearly 48 times more
By contrast, legal sports lotteries in Japan generated just ¥133.6 billion (€794 million) in sales in the 2024 fiscal year, roughly 48 times less than the illegal overseas sports betting market.
Under Japanese law, gambling is heavily restricted. Only a few government-authorised forms of betting, such as horse racing, motorboat racing and cycling, are allowed. Even if an online gambling site operates legally abroad, residents in Japan who use it can face criminal penalties. Repeat offenders may face fines of up to ¥500,000 (€2,970) or up to three years in prison.
Authorities say a key issue is that many residents remain unaware that betting on overseas sports sites is illegal. This has been compounded by a sharp rise in Japanese-language gambling sites and targeted advertising on social media platforms.
According to Japan’s National Police Agency, 279 people were arrested in 2024 for involvement with online betting sites – a 160 percent increase compared to the previous year.
Internet access fuels the issue
In the past, users would access such sites at specialised locations in entertainment districts. Now, smartphones and digital payments have made online gambling far more accessible to the average person. Most users purchase betting points by transferring money via bank accounts or credit cards.
A government survey earlier this year found that 3.37 million people in Japan had experience using online gambling platforms, with 43.5 percent unaware that such activity was illegal.
Despite the growing problem, Japanese authorities face challenges enforcing laws on websites based abroad. The sports council plans to hold discussions with overseas organisations to counter illegal cross-border betting. It aims to raise public awareness to protect athletes and preserve the integrity of sport.
