Tattoos

Tattoos in Japan have a varied history and reception. Culturally they're taboo, since they're associated with the Yakuza, who get them as a commitment to their new way of life.
Banned in many bath houses, tattoos are considered a form of intimidation for those who aren't in the mafia. As part of the crackdown on yakuza, tattoo artists in Japan are required to have a medical licence.
More and more rockstars and other icons get tattoos now, though it doesn't seem to be the traditional designs depicted in the yakuza tats. Also the Ainu (an indigenous people in Hokkaido) adult women used to tattoo their mouths and hands, though today paint is used.

In Japanese some of the words for tattoo include:

wabori

traditional designs

youbori

western designs

horimono

traditional tattoos (literally: carving, engraving)

irezumi

ink insertion (can refer to the forcible tattooing of criminals in the Edo period)

tattoo

タトゥー (katakana of the English word)

The traditional method uses specialized ink (that develops and becomes more vibrant over time) and is inserted with needles attached to a wooden stick and hand poked into the skin. It's expensive, time intensive and painful.
In Western style tattooing the customer tells the artist what they want.
Traditional is different in part because it often covers a large portion of the body. The customer comes in with an idea and the artist can refuse. If accepted, the artist will work with the customer to have the best overall design.

Traditional motifs are highly personal, with symbolism in the designs. they may tell a story or state the person's personality. Here are some of the motifs and common meanings.

Koi

fortune and endurance

Dragon

wisdom, strength, bravery

Phoenix

triumph, redemption

Snake

good health, prophecy, power

Samurai

code of the warrior, courage, loyalty

Cherry Blossoms

life and it's fleeting nature, renewal

Oni Mask

punishment, behavioral code

Tiger

protection, the wind (elemental animal), strength, courage

Skulls

change, cycle of life, death

Foo Dog (Lion)

protection from evil and danger

Severed Head

fearlessness, bravery

Peony

wealth, carefree

Chrysanthemum

symbol of imperial family

Maple Leaves

time passing

Louts

struggle, reaching potential

Water

life, powerful force

Our main character, Umeji Tatsuya, also has Kitsune in his tattoo designs. To him they represent protectors. They're also his favorite characters from mythology.

Japanese Tattoo (late 1800s) by Kusakabe Kimbei