Glyphs
The dakuten resembles a quotation mark, while the handakuten is a small circle, similar to a degree sign, both placed at the top right corner of a kana character:
- ◌゙: dakuten, Unicode U+3099 ゙ combining katakana-hiragana voiced sound mark (HTML:
゙)
- ◌゚: handakuten, Unicode U+309A ゚ combining katakana-hiragana semi-voiced sound mark (HTML:
゚)
Both the dakuten and handakuten glyphs are drawn identically in hiragana and katakana scripts. The combining characters are rarely used in full-width Japanese characters, as Unicode and all common multibyte Japanese encodings provide precomposed glyphs for all possible dakuten and handakuten character combinations in the standard hiragana and katakana ranges. However, combining characters are required in half-width katakana, which does not provide any precomposed characters in order to fit within a single byte.
The similarity between the dakuten and quotation marks (") is not a problem, as written Japanese uses corner brackets (「」).
Read more about this topic: Dakuten