Luca Ortis is an excellent tattooist that specializes in stylistically enhanced Irezumi. Check out this outstanding array of his tattoos of dragons, koi, masks, tigers, and more.
Ortis illustrates excellent koi as well. His renditions of this timeless motif within the style are exquisite. They seem to swim, among the fallen leaves, up and down the river-like appendages of his clientele.
Some of Ortis' most compelling tattoos are of tigers. The way he illustrates them boldly with territorial expressions, wide stripes, and heavy orange and brown saturation makes them roar with ferocity. It's also riveting how he borders them with flora like peonies and maple leaves, similarly to his koi. These pieces put Shere Kahn and that puss, Tony, to shame. They're more than great.
Check out Luca Ortis over at his Instagram. Also, he tattoos in London, so if you're near there and want some astounding traditional or more unconventional Japanese style work, hit him up on his website.