Besides the art, you know what really sold me on this doujin?
How many times do you here the girls going "no, not there! Stop it!"
Exactly.
It's a pretty tired trope in hentai where the uke is totally into it, but gets all embarrassed and begs the seme to stop, even though if they stop, they'll just blush and ask for more. Here? The girls just want to **** each other. Period. And it's glorious. Could've used more cunnilingus, but that's a nitpick.