I really love how Tatsubon not only recognizes that physical intimacy and sex is a natural and important aspect to the vast majority of healthy relationships, but isn't afraid to show it. Heh... Even more, I'm happy that the awkward uncertainty that can accompany a couple's first time, as well as the happiness of their "basking in the afterglow", is on full display. :)
I'm also trying to think of other (non-hentai) romance Yuri, with an actual plot, that have also addressed this in one way or another.
So far, I have:
Bloom Into You
Octave
Husky and Medley
Asagao to Kase-san
and Pulse (even tho it's a manhua and the sex scenes are quite a bit more graphic)
Anyone have another title to add to the list?