Information on Japanese Writing.
Japanese is generally written to the JIS code standard, in double byte format, and contains approximately 6400 characters. Most of those characters are Kanji, which are based on the Chinese writing system. However Japanese has two additional pieces to its written form - hiragana and katakana. Hiragana is most frequently used as verb endings, prepositions and the like, although some Japanese words are written purely as hiragana. Katakana is most frequently used in writing foreign words that have been taken into Japanese. On a business card for someone from the US, for example, the persons name, the company name, and most likely the address, would be written in katakana.
Although Japanese was traditionally written from top to bottom and from the right side of the page to the left, most Japanese material produced in foreign countries is now written with the same orientation as English. It is also almost always written in a fully-justified style, meaning both the left and right margins are flush. Japanese does not generally have spaces between characters and words, as does English. It is most often written as one continuous string of characters. Although Japanese can break almost anywhere in the line, there are certain constraints. Software that has been localized for Japanese will normally handle those situations correctly.