It relies on Matsu losing control like he almost does with Saki, but not remembering it happening, with Hiroko lying to he doesn't crumple under the weight of the guilt. With Matsu fucking all his daughters, and already getting a surprise incest reveal with another character, it would kinda leave a "Mao is Matsu's bio daughter" reveal a little redundant. Despite that, I still like this theory cause I find Dad/Daughter hotter than Brother/Sister
Yeah, I agree. It's easier access, and I can see the whole "mother blames daughter that her dad raped her" thing, playing out. Though I could also see Matsu's dad doing it to spite him for cucking him.
So, is this a detail not even Patrons know?