Considering what you're looking for, it sounds like anime where there are cupids would do?
"30-sai no Hoken Taiiku," the various cupids' role is to make the protagonists get together, and for the whole show they go out of their way to make it happen (watch it alone, it's not R-18, but I'd call it R-17.5
"Ochamegami Monogatari: Korokoro Pollon," to a degree, as Cupid is a cupid after all, but it's not so much focused on him. There are a few episodes about love, and IIRC one episode was about Pollon throwing arrows around to form couples of any kind and fetish, much to the viewer's lulz (this is a kid-safe show, I swear
As a last ditch effort with the cupid search, anidb gave this to me: "Bit the Cupid
" ─ I have not seen it, thus I have no clue if this can do.
Out of cupid territory, "ToraDora," in the second half, could do. They help each other to get to the respective beloved one. I think
"Lovely Complex" did this too in the beginning...
"Aoi Bungaku Series" ─ specifically the "Kokoro" arc, as that is quite honestly perfect for what you're looking for, I believe (not directly protagonist helping the girl, somewhat more indirect, but it might do). The "No Longer Human" arc also covers netorare, which in a way might be a genre close to what you're looking for, but that's most often than not about R-18 content. Pretty much the only non r-18 titles in the category on anidb, aside from Aoi Bungaku, are School Days (which is pretty borderline and not what you want), and Colorful (good movie, but, again, it's not really about what you want).
PS: Little Busters' going to unfold a story different from what people expect (unless said people already know it), to be honest, and it's bad anyway.