Gambling in Japan can be a bit of a puzzle for travellers. While most forms are...

https://varimail.com/articles/what-is-the-best-first-legal-bet-in-japan-for-a-newbie/

Gambling in Japan can be a bit of a puzzle for travellers. While most forms are illegal, there are some unique exceptions where betting is allowed, like pachinko parlours, horse racing, keirin cycling, and kyoutei boat racing