I think I'd like this author more if not for all the incest. :/
She's definitely been reading a lot of Mochi Au Lait, let's leave it at that.
However, I want to ̵g̵l̵o̵a̵t̵ point out that even in early Yuri Moyou days, it struck me as odd that the 4th sister was basically dating the third sister. Her (older) girlfriend could have been her (just older) sister's twin. I got a siscon feeling off her from the outset.