This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Katakana's original purpose, marking pronunciation in the margins of Buddhist texts, has almost nothing to do with how the script is actually used in Japan today. Modern katakana is the script of the foreign and the new: loanwords borrowed from English and other languages, the names of foreign people and places, onomatopoeia representing sounds, and text a writer wants to visually emphasize, the rough equivalent of italics in English. A word written in katakana signals to a Japanese reader, at a glance and before they have even parsed its meaning, that they are looking at something borrowed, imported, or set apart from ordinary native vocabulary, a function no other script in the writing system performs. That shift took centuries: standardization into a clean, one-sign-per-syllable system, matching hiragana's own coverage, was not fully complete until roughly the fourteenth century, and katakana's everyday role as a marker of foreignness is a comparatively modern development layered on top of a script that began as a scholarly annotation tool for sacred Chinese texts. Its spare, angular letterforms, a direct legacy of being built from character fragments rather than whole cursive shapes, still visually set it apart from hiragana's rounder strokes wherever the two appear side by side.