Quote from YandereDev:
"Who’s she? The hair definitely reminds me of someone. Or was it two someones? Or was it…three? Somehow, I get a headache when trying to remember the third one…"
Could this be...Megami's Aunt's lost twin?
(If you don't understand what I'm talking about, listen to the Headmaster Tapes, then read this wiki's page on "Fun Girl")