I'm not sure if this is the right thread to do this in, but I wanted to put forward this idea:
What if Hazumu had
Klinefelter's syndrome or was a
Chimera in his male form. Thus when he gets dusted by the space ship, his Y chromosomes were lost and they had to rebuild from the XX left over.
This could explain how he seems to have gender identity issues and provides a plausible explanation for the sex change.
Of course, there is the outside-the-4th-wall-element that this is an anime made for boys and follows certain patterns...
