This VN essentially took pretty much all variants of NTR and ran with it. Village ritual, rich bastard, manlier man, other friend, second chance, blackmail, and even just normal drifting out. Amazing, in the variety, I have to say.
If I didn't do the Happy Ending first though, I don't think I could care about the main character. Honestly, he's a total wimp. Even when he got encouraged by the two's past selves, it took so long for him to act on it or even change. I'm mostly just encouraging the girl because she's really cute in that route. I don't know how it'll change things though, since the ritual is still a thing, and he's still moving out.
By far, my favorite is Daisuke, the co-worker's route. Yeah, he's pushy and loud, but I gotta love that earnesty and when you contrast with how the MC was just "playing cool" even though he's anxious as hell, Daisuke is actually worth rooting for by contrast. By the same token, I kinda like the Vagrant route as well, though to a much lesser degree (especially since he's even more of an ugly bastard). Still, kinda happy for the guy to have his second chance at happiness despite everything.
The Masaru (other childhood friend) and Oyama (village slut) routes are just okay. The main appeal for me are the sex in those routes, not the story, but they do have their own thing going. Nobuo is just a whiny rich kid though, he's basically even more pathetic version of the MC, except he can win, which doesn't endear me further. And Yasui is just blackmail route - it's literally the most hentai manga series to me, and about what we actually expect with regards to NTR.
I kinda feel sorry for the big sister, even if we go Happy End and didn't see a single sex scenes, she's still stuck there and she's still getting fucked. With the way the Vagrant route with her went, I think she still has her morality which is what makes it more painful to me. The old man shopkeeper route was just ehhh to me though, it's boring in contrast to everything else.
All in all pretty good if you're looking for NTR, though if you're not then this isn't the game for you. Yes, there is a Happy Ending, but you don't get any H out of it even if it is pretty sweet.