A general term among body modification
enthusiasts for any tattoo
based on asian writing systems, including Japanese kanji
and Chinese hanzi
They and those who wear them are not highly regarded due to their tendency a) to be chosen "because they look cool" as opposed to personal significance and b) to be completely incomprehensible to the person they are tattooed on. Urban legends abound of people having kanji tattoos that look nice but have unpleasant meanings. This can be caused either by falling in love with the wrong character and impressing it on an illiterate tattoo artist or in some reported cases, as a result of malicious tattoo studios happily tattooing that unpleasant phrase they have hanging on the wall. "This dish, while tasty, is also cheap" is a favorite, and lawnjart says he knows someone with "I am a lover of large quantities of ass". Looking at more pleasant choices, Buddhist symbols such as Om are also popular, as well as getting your name in Asian characters. Watch the translation on this - only katakana can give a proper translation. Anything else is pretty subjective.
The movie Pretty Woman is blamed for the popular introduction of kanji tattoos, since Julia Roberts had a character which she claimed meant "strength of heart". Fittingly enough, it actually means "strong" as in brute physical strength. Personally, I think these things are kinda stupid for the aforementioned reasons, but it's not my body.