While the Japanese script is used by just a single nation (~2% world population), the economic power and cultural influence of Japan placed it well among the world’s most-recognizable writing systems.
Every character is of the same height and width. Japanese script is written top-to-down traditionally but left-to-right writing direction is also popular today.
Japanese script (kana) letters
Nearly every Japanese character means a simble syllable (a consonant and a vowel). Some characters means single vowels. Diacritical marks above the characters modify the spelling in some particular way.
Every Japanese letter has two forms (sometimes called two scripts): hiragana and katakana. Which form to use depends on context. The words of local and Chinese origin are written in hiragana while those of foreign origin in katakana.
Furthermore Chinese script (kanji) is also used for some Japanese words.
Japanese script uses no spaces.
History of Japanese script
By 4th Chinese script reached the Japanese islands together with Mahayana Buddhism and Chinese language. Chinese script was however ill-suited for Japanese language that has a very different grammar.
Every Chinese character thus acquired two readings: “on” (Chinese loanword) and “kun” (synonymous Japanese word). This was not enough however as Japanese words differ based on circumstances yet there was just one Chinese character for all forms of the word.
Some Chinese characters thus began to be used for syllables rather than words. This made sense as Japanese has relatively few possible syllables. Over the time these characters were simplified and became hiragana by 5th-11th centuries AD. Still the educated people wrote Chinese language and script.
Katakana developed independently in a similar fashion in 9th-14th centuries AD (developed by Buddhist monks to mark holy book pronunciation).
Until early 20th century every syllable had more than two characters in kana. The reform of left only the hiragana and katakana forms while the rest became deprecated as hentaigana.
The sphere of Japanese script was directly related to the power of Japan. In the 1860-1945 colonial era the script was used more widely as Japanese people settled the colonies and colonial languages also made to use Japanese script in some way.
After Japan lost World War 2 and lost colonies however the script once again was limited to the Japanese islands but the rapid modernization and rising exports made it recognizable all over the world.