New Goal!

Oh that makes sense. My line of thinking was that because Mizue was in The Other Side, and had memories of being both their grandfather and Jamie, Mizue would be the one to identify as male and dress feminine because of the memories of Jamie's wishes to dress feminine that had to pushed down as they had to dress in drab. Therefore Jamie would be a tomboy that wants to breakout into their feminine side and still identifies as a cis-girl which they have stated they are multiple times, and with Mizue being the femboy that existed beyond the power and usability of their grandfather in the Other Side. Thus no lines of logic nor lore rules are broken.

[spoiler warning] A good question, but no Jamie would be the male and Mizue would be the female. Jamie would have been the form of the vessel and if everything had gone as planned, there would have been a pair of male twins.

I beg your pardon, but wouldn't it make more sense if Mizue was the femboy?