[dirtyroboto]

From my understanding of the Japanese issue with tattoos stems from two areas.
The first has been covered in the gang type posts.

The second is a more basic and simple fact. The Japanese feel that only weak minded and those of impure spirit feel the need to deface their body.
It is seen as an overt sign of self mutilation. Like being proud of your failed suicide attempts by showing off your scarred wrists.
Failure to forfill a suicide is a good sign that you are a weak person, just like getting some "good for now" sign scratched onto your body is a good idicator that you are weak and predisposed to bolstering your self image by using a better substitute that you can use to deflect attention away from your issues.

Also it is offensive for other people to look at your tattoos, not everyone need to see what you think is cool.
Just buy the tee shirt, a thing that can be taken off and changed with the season.

As for the muslim issue. The only people with problems concerning this are the muslims. Everyone else is bored to tears with the whining and moaning of this hard done by, and greatly oppressed group (of racist and sexist religious maniacs).