Japanese writing system

The modern Japanese writing system (日本語の表記体系, Nihongo no hyōki taikei) uses a combination of logographickanji, which are adopted Chinese characters; and phonographickana, which evolved from cursives/components of Chinese characters. Modern kana consists of two sets of syllabaries: hiragana, used primarily for native or naturalized Japanese words and grammatical elements; and katakana, used primarily for foreign names, loanwords (gairaigo), onomatopoeia, scientific terminology and sometimes for emphasis. Almost all written Japanese sentences contain a mixture of kanji and kana. Because of this mixture of scripts, in addition to a large inventory of usable kanji characters, the Japanese writing system is considered to be one of the most complicated currently in use.

Several thousand kanji characters are in regular use, which mostly originate from traditional Chinese characters. Others made indigenously in Japan are referred to as "Japanese kanji" (和製漢字, wasei kanji), also known as "[our] country's kanji" (国字, kokuji). Each character has an intrinsic semantic meaning (or range of meanings), and most have more than one pronunciation, the choice of which depends on context. There are 2,136 commonly used ones (jōyō kanji) as of 2010, and Japanese school students are required to learn 1,026 characters (kyōiku kanji) before graduating sixth grade. The total number of kanji is well over 50,000, though this includes tens of thousands of characters only present in historical writings and never used in modern Japanese. Despite the complexity of writing kanji, modern Japanese texts without kanji are rare; most are either children's books — since children tend to know few kanji at an early age — or early electronics, including computers, feature phones and video games, which could not display complex graphemes like kanji due to both graphical and computational limitations of the hardware and software.

In modern kana usage, hiragana and katakana syllabaries each contain 46 basic characters (which can be organized using the gojūon), or 71 including diacritics, in their alphabet sets. With one or two minor exceptions, each different sound in the Japanese language (that is, each different syllable; strictly, each mora) corresponds to one character in each syllabary. Unlike kanji, the only function of kana characters is to transcribe pronunciations; they can only convey semantic meanings after forming words. Although hiragana and katakana characters both derived from the earlier man'yōgana — which are Chinese characters used as loangraphs during the Nara period for phonetic transcription using their Middle Chinese pronunciations — their forms have been simplified/modified to such an extent that they are no longer visually obvious to their grapholinguistic origins.

To a lesser extent, modern written Japanese also uses initialisms from the Latin alphabet, for example in terms such as "BC/AD", "a.m./p.m.", "FBI", and "CD". Romanized Japanese is most frequently used by foreign students of Japanese who have not yet mastered kana, and by native speakers for computer input.