Nah, he was introduced to the reader in chapter 13. Yuushin was also made aware that the dad was in on the conspiracy with generic Miyu in that chapterThis chapter I believe
Chapter 13The father showing up out of nowhere is kinda sus. They’ve been working together secretly but Yuushin had no idea until now. Feel like he should have more of a major role or at least been introduced way earlier.
I'm so glad I'm not the one who had this dread this while fake Miyu was doing a monologuewait are we supposed to be under the impression that yuushin did it and he has been and unreliable narrator this whole
time?
This would work if there's no physical difference that's being said in early chapterMaybe it's a double personality sort of deal? OG Miyu's personality died and got substituted by New Miyu, who was dormant or way less dominant before, with their scenes together at school being allegorical.