While many gambling platforms legally operate outside of Japan, using overseas sites to bet from within the nation still constitutes a criminal offense.

The revised law on countermeasures against gambling addiction, approved by the Upper House, explicitly outlaws the establishment and operation of online casinos and related apps within Japan and also prohibits attempts to funnel users to overseas gambling platforms, even if those sites operate legally in their home countries.

The new legislation — expected to take effect three months after its promulgation later this month — targets a wide range of promotional activity, including banner ads, ranking and recommendation sites, and posts on social media that spark user interest in online casinos. What are known as “reach sites” that list “top 10” casino picks or provide affiliate links will be deemed in violation of the law.

While the revised law carries no clear criminal penalties, it makes such activity explicitly illegal, allowing internet service providers and social media platforms to remove content more proactively. The National Police Agency (NPA) said it expects the move to help suppress access to such sites.

The Internet Hotline Center, which monitors harmful online content on behalf of the NPA, is also preparing to classify such content as “illegal information” and issue takedown requests. Ahead of the law’s enforcement, the agency plans to publish guidelines outlining what specifically constitutes a violation.

According to NPA estimates, roughly 3.37 million people in Japan have engaged in illegal online casino gambling, with total wagers reaching an estimated ¥1.2 trillion ($8.3 billion) annually. Though many of the sites operate legally in jurisdictions such as Curacao, accessing them from Japan and placing bets violates domestic anti-gambling laws.

To stem the flow of Japanese users to overseas platforms, the NPA has also requested that foreign governments restrict access. Through the Foreign Ministry, the agency has approached licensing authorities in territories such as Curacao, asking them to suspend services targeted at Japanese users. These requests include removing Japanese-language interfaces and clearly displaying warnings that use from Japan is illegal.

The NPA is ramping up its own efforts to curb the rise of online casino use among young people, citing a widespread lack of awareness about its illegality as smartphones make gambling sites more accessible than ever.

The crackdown comes in the wake of a series of high-profile celebrity arrests linked to illegal online casinos. Many believe that misinformation online — such as claims that gambling via offshore sites exists in a “gray zone” — and online casino ads featuring celebrities has fueled a false sense of legality.

According to an agency survey, only 40% of those who had used online casinos knew the practice was illegal, with awareness particularly low among people in their 20s.

In response, the NPA is strengthening its public education campaigns, leveraging stadiums, concert venues and movie theaters to broadcast awareness videos.

The agency has also contacted talent agencies representing athletes and entertainers featured in casino ads to inform them that their appearances could constitute “abetting gambling,” and have requested their cooperation in helping them combat the issue.

Authorities plan to distribute 100,000 leaflets with the help of delivery companies and other partners.

While some users initially access online casinos to play free games, data suggest that roughly 75% of them eventually begin wagering real money. Officials believe the new restrictions will reduce the visibility of such platforms and drive down user traffic.

To fully eliminate access, the agency is also considering more aggressive technical measures. One option under discussion is “blocking,” which would forcibly restrict access to offshore sites.

However, such action may infringe upon the constitutional right to privacy in communications. The communications ministry has launched an expert panel to debate the issue and weigh its legality.