Comment by kazinator
I would say, hiragana and katakana, in a way.
Each nominal syllable sound in Japanese can be written using a characater in one of these two scripts:
Roman transcription: a i u e o ka ki ku ke ko
Hiragana: あ い う え お か き く け こ
Katakana: ア イ ウ エ オ カ キ ク ケ コ
There are some rough parallels between upper case and katakana.
- Katakana is used less than hiragana; "katakana heavy" text will be something that is loaded with foreign words (like a software manual) or terms from zoology and botany.
- It is sometimes used to denote SHOUTING, like in quoted speech such as cartoon bubbles.
- Some early computing displays in the west could only produce upper case characters; in Japan, some early displays only featured katakana. It needs less resolution for clarity.
> Katakana is used less than hiragana
Katakana was used much more frequent than hiragana for about a century following the Meiji restoration, regardless of the technical limitation. That can be thought as another parallel though: Latin majuscule letters are (close to) the original Latin script while minuscule letters are derived from them, but now minuscule letters are much more frequently used. The only difference here is that either hiragana or katakana wasn't derived from each other, they share the single origin of simplified Chinese characters.