Instinct
One of the hardest things for him to get used to after the change was the new instincts. The bone deep knowledge of the basics of flying was useful, but things like flapping water off after getting utterly soaked, or knowing what to do and not do about dirty feathers is different. And while the latter was useful, especially during the algae incident, the former was just undignified. A hand in his feathers derailed his train of thought as Daisuke reached the place where wings merged into a seemingly normal human back and caressed the miniscule feathers there, preening them gently. Evidently the root of his wings was a sensitive spot, as the light brush of his partner's fingers over those feathers made him just want to melt. No wonder Daisuke had purred when he was being preened.
Weight
For all their size the wings are surprisingly light and having them out all the time doesn't cause muscle strain or anything of the sort. It is this that makes him wonder just how far the physical changes went, aside from the obvious wings and not entirely human eyes. And when Daisuke had tripped down the stairs and landed on him earlier his friend didn't seem nearly as heavy as the last time they'd collided like that. If only their responsibilities were that light.