Main plot. It turns out Makoto has sort of a bet going with his dad. Mako wants to be an actor, Dad wants him to take over the dojo. If Makoto successfully pulls off living in drag without anyone finding out until graduation, he proves that he has both the acting skills and the sheer bloody-minded stubbornness to do whatever the hell he wants.
Ito thinks this is awesome, basically, and they spend the next couple years working together to keep Mako's identity, and eventually their relationship, hidden from all and sundry.