I had an opportunity to explain gambling in Japan to Minister Hon Ralph Regenvanu during his visit to Japan. However I found that I was slightly wrong, as well I could not explain the whole picture of it.
Let me summarize here, but as I am not an expert on this issue please see the following as an introduction.
Japan only allows public gambling which was established after the WWII to help in the reconstruction of a completely destroyed society and economy.
Horse Racing (Ministry of Agriculture) 25 billion USD
Auto Racing and Bicycle racing ( Ministry of International Trade and Industry) 6 billion USD
Motor boat racing (Ministry of Transportation) 10 billion USD
Lotto (Ministry of Internal Affairs) 10 billion USD
Sports Lotto (Ministry of Education) 1 billion USD
However our biggest gambling is called Pachinko, which looks like a sort of poker machine and has a revenue of 200 billion USD a year. They are not strictly allowed to gamble, and is officially only a game. The customer can only obtain materials such as toys, candy etc. However, there is a way around this - a trick which I could not precisely explain to Minister. That is, the customer also gets a small box, which he/she can exchange at a totally different shop for "real money". This tricky system barely keeps their legality.
Now the Abe government will try to introduce a new Casino bill which may replace Pachinko - shady gambling.