Alphabetic text in Japanese fonts are primarily designed for documents mainly in Japanese with the occasional Latin script jargon. There's a variant (full-width

Alphabetic text in Japanese fonts are primarily designed for documents mainly in Japanese with the occasional Latin script jargon. There's a variant (full-width) that's sometimes used that indeed is very wide, made to be of the width of the Japanese kanji, but even the proportional ones are pretty light and widely spaced (which results in better typography in mainly-Japanese documents)