Japan’s Largest Suspected Online Gambler Arrested After Wagering Over $625,000

Japanese authorities have apprehended Makoto Chomabayashi, a 38-year-old man believed to be the country’s largest individual online gambler.

• Chomabayashi confessed to spending approximately 90 million yen (~$625,000) on a single illegal global online casino, primarily playing baccarat.

• Police tracked his gambling activity from August 2022 until his arrest in April 2025.

• Investigators speculate that the actual amount he wagered could exceed 28 billion yen (~$195 million), potentially making him Japan’s biggest online gambler in history.

• Despite knowing the activity was illegal, Chomabayashi gambled under the belief he would not be caught.

• He stated that the casino environment gave him a sense of recognition and excitement after wins, which fueled his continued gambling.

• Unlike some other cases, Chomabayashi is not suspected of any illegal funding sources; the money wagered appears to be legally obtained.

• This case is part of a wider crackdown on illegal online gambling in Japan, where authorities target not only operators but also consumers.

• The National Police Agency estimates 3.37 million people in Japan gamble illegally online, spending over 1.24 trillion yen (~$8.6 billion) annually.