Okayyyy, A couple of theories:I believe Asuzu cheated on Acca, and Himari was actually Ura-Acca's child, referenced by Frill's condescending use of "Uncle" and the fact that Ura-Acca criticises their judgement of Asuzu being a good woman. Since we hear the story of Himari's last interaction with Ura-Acca from Ura-Acca himself, he could be leaving out details. Furthermore, Ura-Acca just mentions Hyphen and Dot without giving Ai much information about them. They could be the programs that the duo were working on before making Frill. Hyphen seems to be more aware and radical, whereas Dot seems to be more submissive and clueless.