U+309C "゜" Katakana-Hiragana Semi-Voiced Sound Mark Unicode Character

U+309C "゜" Katakana-Hiragana Semi-Voiced Sound Mark is a diacritical mark used in the Japanese writing system, specifically to transform certain kana characters into their semi-voiced counterparts. It appears as a small circle placed above the top right of a kana character, such as turning "ハ" (ha) into "パ" (pa), indicating a shift from an unvoiced consonant to a plosive bilabial sound. This mark is applied to the hiragana and katakana of the H line (ha, hi, fu, he, ho) and the P line in modern usage, and it plays an essential role in accurately representing both native Japanese words and foreign loanwords. Unlike the tenten, which indicates a voiced sound, this semi-voiced mark specifically denotes a change to a "p" sound, making it a distinct and vital component of the Japanese syllabary.