Comment by numpad0
IMO: quality wise, FOSS fonts are fine(n=1) - it doesn't have to be a proprietary font but do have to be the right ones of CJK.
- In cases with the Noto project, they've given up long ago on literal singular font in both name and file to cover every languages; they have bunch of variants as different fonts(TC,SC,HK,JP,KR,...), available as both individual files as well as combined files[1].
- In cases with most Latin fonts like Deja Vu - I think this is where bulk of "wrong font" problem comes from. They don't support CJK at all, and operating systems often handle fallback to system defaults for missing characters, but sometimes OS falls back into wrong CJK fonts and cause text mIshmashlnG[2] problems or show bunch of square placeholders(aka tofu). The latter is usually solved by installing Noto fonts, and former by specifying what fonts are to be used for fallbacks(anyhow it's done, it can be OS or game engine dependent).
- There are also bunch of domestically made fonts such as IPA Gothic; they usually only support the targeted one of CJK + ASCII(+ISO-8859-1). Most Japanese-English _bi_ lingual contents take this route, which had lead to curiosity by some as to why Japanese content creators appear to have unique and specific taste for fonts[3] - in fact they're just reusing the font files already in the project folder.
- For creative purposes such as games, FOSS fonts sometimes don't cut it, but that is not unique to the Japanese language.
1: https://cdn-ak.f.st-hatena.com/images/fotolife/s/satob/20231... | https://archive.is/6qeVm
2: https://blog.enjo.life/wp-content/uploads/2022/08/fonts-and-... | https://archive.is/jSQzn
