Oh wow I was jokingly saying that this girl is Uryu's kid from Tying the Knot with an Amagami Sister but that last page confirms it. Man I miss that manga & I was fine with the ending but I was confused whether on the whole the alternate worlds marriage thing plus if they are aware of it. If anyone that reads that spoiler & knows what I'm talking about then I would like a clarification since thinking about it again, I'm uncertain about those last 7 chapters. Thanks for translating this Twitter short.