Japanese officials have two individuals for allegedly operating a website that promoted an overseas online casino and facilitated illegal gambling, including habitual play. The website, named Onkaji Hissho, reportedly promised “guaranteed wins” to attract customers, drawing an estimated 670 users over a four-year period.
Investigators said customers were encouraged to place bets totalling around ¥70 billion (€470 million), with the defendants receiving substantial commissions from the casino in return. The case is prominent as the first in Japan targeting a website that advertises online casinos to Japanese players.
Over 600 individuals hit
The suspects include 40-year-old Hisato Yonezawa, an executive from Osaka, and a second unnamed individual. They allegedly ran the site alongside a paid Discord group called “Onkaji Hissho Club,” which offered detailed “winning strategies” for ¥10,000 (€67) per member. Around 300 people reportedly joined the group.
The website gave users instructions on how to register at a Curaçao-licensed online casino, according to official statements. In contrast to traditional affiliate models, the defendants signed a “affiliate agreement” with the casino in 2021, whereby they would receive commissions based on total bets placed rather than customer losses. There have been reports of transactions involving cryptocurrency, such as Bitcoin.
Gifu Prefectural Police’s investigation revealed unlawful business practices and collusion with foreign operators for financial gain. Police emphasised the sophisticated strategies employed to draw in and keep users, pointing out that the website advertised itself as “completely different” from other platforms and only provided helpful information in order to win users’ trust.
First arrests after new laws enacted
The arrests come as Japan amended new regulations for online gambling, enforced from 25 September 2025, banning online gambling advertisements and the launch of new overseas casinos targeting Japanese users. Passed in June 2025, the law banned celebrity endorsements, affiliate websites, ranking platforms, and promotional links aimed at residents. Social media platforms and websites must remove gambling-related ads if instructed by authorities.
While online casinos remain legal abroad, accessing them from Japan is prohibited under the Penal Code. Around 3.37 million Japanese residents, mostly in their 20s and 30s, engaged in online gambling, wagering an estimated ¥1.24 trillion (€8.3 billion) annually. Advocacy groups have warned that gambling-related deaths may be underreported, though official figures show 398 fatalities linked to gambling debts.
Authorities emphasised that profits from online casinos flow to operators, not players, and urged the public to avoid participating in advertising or affiliate schemes. Officials also announced public awareness campaigns highlighting the risks of online gambling, including social harms and legal consequences.
Multiple reports show the gravity of the situation. Japanese residents placed ¥6.45 trillion (€43 billion) in bets on overseas sports gambling in 2024, raising concerns over match-fixing and athlete safety. Despite these restrictions, regulated gambling remains available domestically, including horse racing, government sports betting, and pachinko. Plans for Japan’s first integrated resort, MGM Osaka, stay on track for a 2030 opening.
This explains why Japan is cracking down on online gambling. With the aim of providing economic opportunities in entertainment and tourism with robust protections against gambling addiction, particularly among younger generations, the country continues its strict surveillance.
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