I agree with Nyororin, do not romanticize the yakuza. They are a part of organized crime. The fundamental structure is like the presentation of the Italian mafia in The Godfather or Goodfellas: They have to have a presence, and a positive one in their immediate community. It's once you get mixed up with their business you have things to worry about. (Think of the restaurant owner in Good fellas who asks for a loan from the local Don, and ends up having his business liquidated and finally torched.)

This is from famous film director Juzo Itami's page in Wikipedia:

In 1992, Itami was attacked, beaten, and slashed by five members of the Goto-gumi, a Tokyo yakuza gang, who were angry at his portrayal of yakuza as bullies and thugs in his film Minbo no Onna. This attack led to a government crackdown on the yakuza. His subsequent stay in a hospital inspired his next film Daibyonin, a grim satire on the Japanese health system.

If you would like to know more watch the movie Minbo no Onna. It is a crash course on how a yakuza gang can make life hell for a business that doesn't kow-tow to them (in this case a hotel).

Minbo - Wikipedia, the free encyclopedia

The pool is five minutes walk from my house. I've been using this facility for 15 years without any problem. I'm not thinking of suing, I just want to know if I'm within my rights to to refuse to cover up.

This is at a sports centre in west Tokyo. The word was the Japanese for gang member. I think it was 暴力団員. (There are no English rules).

As I said, I don't see how they can refuse even gangsters if they are not doing anything illegal. If they are doing something illegal then put them in jail.

[quote=Philotus;810091]This is at a sports centre in west Tokyo. The word was the Japanese for gang member. I think it was 暴力団員. (There are no English rules).

Sorry. I just checked the rules and it seems gangsters are not actually banned. My poor Japanese is to blame.

Ah, I understand.
Good luck.

I would not think so. They are not denying you access to the facilities - they are asking you to follow the rules and giving you a way to do so (by covering your tattoo). By refusing to cover up you would be breaking the rules, and they would be within the law to refuse you access.

If they haven`t asked you before now it could be due to a number of different things. It could simply be that they have not noticed until recently... Or that they have started really cracking down on things like that... Or that they have started to apply the rules equally to all residents using the pool (in the past, a lot of places would be more lenient to foreigners not following the rules - basically giving them special treatment. This is decreasing quite a bit recently and foreign residents are being treated more equally - in all ways including being asked to follow rules like that pool one.)... Or there could have been a complaint.

I have since spoken to a gentleman whose job includes asking people with tattoos to cover up at public pools. He informs me that he can only ask, not insist, as it is a public pool. I will politely refuse next time.