I really don't think Yuu wanted to be a woman, usually he didn't even act like one and even dressed up he was very manly.
Some dudes just like dresses. I felt this was a nice touch on that idea without having the overly feminine 'oh I'm just a flat girl with a peen' shtick that some yaoi have.
i don't like womanish/girlish yaoi. manly yaoi is the best! reading this manga is waste of time.....