U+309A "゚" Combining Katakana-Hiragana Semi-Voiced Sound Mark Unicode Character

U+309A "゚" Combining Katakana-Hiragana Semi-Voiced Sound Mark is a combining diacritical mark used in the Japanese writing system to indicate that a syllable, typically beginning with an 'h' sound, should be pronounced with a semi-voiced or labialized sound, such as turning 'ha' into 'pa' when attached to a kana like は. Unlike the regular voiced sound mark (dakuten) which adds a voicing, this small circle diacritic (handakuten) specifically denotes a bilabial plosive or fricative, and it is combined with the base character in digital text to form a single grapheme that modifies the pronunciation of the kana it accompanies.