part alternation mark; Unicode U+303D symbol
A Japanese typographic symbol (〓) used to indicate that the following text is a song or that the speaker is singing. Also known as the 'iori mark'.
The part alternation mark is used as a symbol to indicate the start of lyrics.
Unicode U+303D is assigned to the part alternation mark.
The name 庵点 (いおりてん) likely derives from the symbol's resemblance to the roof of a hermitage (庵). The exact origin is uncertain.