As I am giving a side-hug Leo, wanting to convey that I still cared about him as much in my magical-girl form as I do when a boy, he look at me and note "You explained how it change you in the brain, but what about the body? What it feel like to be a girl?"
Wanting to answer as precisely as possible, I think on it for a bit and rapidly notice I lack words to do so. "I’m very tempted to simply answer 'different', but you deserve a better answer. First, I somehow can feel my internal organs aren't arranged exactly the same to make place for my vagina, uterus, and ovaries, even if I can't fell how exactly."
"What's a vagina and the rest?" interrupt my little brother.
Realizing I might have spoke of things I shouldn't, I try to correct the shot as best as I can. "Let's just say it's organs that help adults women with having children." I half expected him to ask how, but instead he said "Ohhh, that's that's where futures moms stock their babies!" It made me smile.
"I also feel how much my hips move when I walk, though it's also a consequences of my different 'equipment', and my breast moving with each steps, as small as mine are. There's no way I would walk around around without a bra as a girl! And I also understand all the better why mom's so cross each time she find the toilet's seat was left up."
"Why?"
"Because girls can't pee standing up, they need to sit to do so. But none of that is a problem, if anything it reaffirm to myself my status as a girl when transformed, something I find really reassuring while in this form. That said, there is one thing I'm apprehensive about being female, but it's something no girl want to discus with a boy, not even when they sometimes are one themselves…"
I am speaking of my periods, in case you didn't guess. Lumina, or rather Dr. Judy Hall, had explained that, as a magical girl, my body was fully functional, and I would soon go through my first periods. What is unknown is if being in boy-mode will push my menstrual cycle until I turn into a girl, or if I will turn to my magical-girl form against my will because it's my time of the month. Either way, I'll probably be unable to change back until I stop menstruating for the month.