Mistery Japan Token? (Id: Pachinko Token)

Google Lens: "This appears to be a Japanese pachinko or amusement game token. Such tokens are used in game machines in Japan, and are often made of copper-nickel or nickel-plated brass.
Translation
[The text on the token reads "Suntan" or "Santoan", likely the name of the pachinko parlor or arcade where it was used]. "

Pachinko, and it's electronic version pachisuro, are very popular gambling-games in Japan. Gambling on most things is illegal in Japan, but pachinko parlours are a loophole since pachinko is classed as a "game of skill", not "game of chance" - and legal to gamble on, so long as the players don't actually win cash prizes. Instead, they win things like toys, cigarettes, candy, or these tokens.

Across the street from every pachinko parlour is a "token shop", owned by the same (usually shadowy underworld-linked) organization that owns the pachinko parlour, where you can go and sell your tokens for actual money. Thus, the lucky players can ultimately walk home with cash winnings, and nobody is technically breaking any laws.

There are thousands of different types of pachinko token; I'm not aware if anybody (either in Japanese or English) has attempted to catalogue them.

I brought back a Pachinko machine from Japan in 1978. Mine used steel balls.