True that, I cant get into many pools with my tattoo, even though its 入墨 and not 刺青. Then again, recently, there is a lot of young people (even on TV!) with fashion 入墨. Perhaps there will be a distinction soon between those two.
Onsen - it also depends, some will let you in some will not. With irezumi is a fat chance, but tattoo (even though mine is in kanji) its usually OK, especially when I explain that it is my 書道雅号. Sometimes I have to write it on a paper, cause older people do not comprehend gaijin+shodou+gagou.
It fries their CPU.
I could not show my tattoo in Gold's Gym...or any gym, but i told them to get lost and get over it, or change their ridiculous manual.
As to the imagery, there is no way I am tattooing a carp on my body, despite its meaning. It's just gay, especially in color. If you are white, color tattoo will look bad, as artificial gold on a hairy and fat drug dealer.