Contrary to most western cultures, but similar to other East Asian peoples, Japanese only bear one given name and one surname, which is placed first. This usually leads to confusion when names appearing in Japanese texts are "westernized" (putting the surname after the given name) in the course of translation, and subsequently swapped around a second (third, fourth, ...) time by others who didn't recognize which part was the surname and assumed that the name was still in its native order. For this reason, many Japanese write their surname in ALL CAPS in the romanization.
There are about 100000 surnames in use in Japan today, which is an insane number considering the size of the country and its nearly immigration-free history (compare this, e.g., with about 6000† names in China with its ten times larger population). One reason for this variety is that during the Meiji Restoration, merchants and peasants who were formerly forbidden to have a surname (this was a privilege of the upper class family clans) were now required to assume one, and if the family registers were lost or didn't indicate any relation to an established clan, people just made something up. Also, changing one's name wasn't a big deal in Japan in former times. Many people did this when relocating or getting any kind of public appointment.
The writing of Japanese names is often a problem, even for native Japanese. With the exception of some female given names which are written in katakana, both given names and surnames are written with one to three (usually two) kanji characters. The relation between the characters used to write a name and its pronunciation varies from "obvious" to "non-existing" (especially with given names). In addition to the 1945 jouyou kanji, there is a list of 284 jinmeiyou kanji which are officially approved for the writing of names. Many of these characters are pronounced in an obsolete, dialectical or idiomatic way, or even in a way that has absolutely nothing to do with the meaning of the character (the kanji were just chosen for their auspicious significance). Because of this, Japanese with more unusual names usually print the pronunciation of their name in kana on their business cards. You can also often see this in Japanese newspapers and the subtitles of TV news and movies.
Some random examples of more or less obscure Japanese names:
- The ubiquitous surname 田中 Tanaka is composed of the ordinary Japanese words 田 ta "rice field" and 中 naka "middle, center, inside".
- The combination 長谷, consisting of 長 naga(i) "long" and 谷 tani "valley", can be pronounced nagatani (obvious), nagaya (less obvious) or hase (as in 長谷川 Hasegawa, a surname). The latter isn't the on-reading of the kanji, either (which would be CHOUGOKU). This is an example of nanori (name readings).
- There are over 150 possible spellings of the male given name Akira, including 明 "bright" (used, for example, by Akira Kurosawa), 玲 "sound of jewels" (pronounced REI, this is also the first part of the name of the main character in Serial Experiments Lain) and 信良 "faith"+"good". Most of the characters used to write the name are related to light, however.
- 栗巣 kurisu "chestnut"+"nest" is one possible way to spell the name "Chris". In earlier times, applying for Japanese citizenship required you to give your name in kanji, but the authorities now also accept foreign names written in katakana.
- Male given names often end in 郎 -rou "son" (Ichirou, Tarou) or 夫 -o "husband" (Tetsuo, Yukio), female names in 子 -ko "child" (Aiko, Keiko) or 美 -mi "beauty" (Mayumi, Naomi).
Many Japanese surnames are originally place names.
† schist informs me that there are actually only about 1000 surnames in use in China.