my god.. di i get theory after reading this...
is a little bit wild in my opinion but, here's.
If you go back to the early chapter maybe 3 or 4.. remember everyone thought Tamaki Arisu was a girl... but in reality.. he's not.
What if... i say what if, Tamaki Arisu actually a girl... but turn into a middle age man at the same time yoko became a girl. Maybe he was the one who pull of the supranatural thing that made them switch gender.
As a matter of fact, in the Pre-Serialization he push Yoko to become more popular then it should be.
well is all theorie, it could be wrong...
but boy, i get over excited when the thought come and want to share it for anyone own opinion.