There are many special types of
irezumi, and highly stylized artistic styles. There are a few recognized masters of this art, and they are relatively unknown due to the still-existent "
taboo" on the art within
Nipponese society.
My particular favourite is one called 'the river', where the tattoos stop at the neck, the upper arm, and the upper thighs; there is an open strip of skin down the chest, so when a man is wearing a short kimono none of the body tattoo will be visible. (this is one of the lesser full body types.)
The most painful area to tattoo in this art form is the penis. the irezumi master mixes small amounts of cocaine in the ink (or at least traditionally), and typically only a square inch can be done at a time before the tattooee passes out from the pain.
I highly suggest looking for books at your local library, there are some wonderful ones out there on the topic which I can't recall at this time.