Thing is, it looked like the editor was fully reigning him in for almost the entire first two volumes. It's only at the exact last page of the last chapter, and then the whole bonus one, that Hagu started ruining the series. I think it's less that anyone is surprised that he went in this direction, and more that they allowed this to be published. If the editor had said "No, you can't retcon the first two volumes into NTR", it simply wouldn't happen. It wouldn't be the first time a series is carried by its editor (https://www.animenewsnetwork.com/fe...ndustry-an-interview-with-aka-akasaka/.197795).
Maybe you think Hagu played it off and said he wasn't going to double down in Volume 3. But he did, and he got a whole additional volume out of it despite 3's horrible sales. What even is the story behind all this?
Hagu could have published all this independently, made it a full porn series with whatever plot he wanted, do any scenes he's forced to imply here, and the audience would be much more receptive to all this. Especially if he didn't try to play this "romance" angle.
I'm in 100% agreement with you, and I actually made a comment about the bait & switch in my next post:
It also did not help at all that the first two volumes did not suggest the NTR and casual sex stuff at all. Sasha was clearly originally going to stick with the wholesome shounen romcom stuff until either Haguhagu could sell his kool-aid to the publishers, or someone let Haguhagu off the the chains (who knows what happened behind the scenes).
and yeah, we'd be having none of this discussion if it weren't for all of that. There's so many ifs: Haguhagu could have self-published all of this. The publisher could have forced or asked Hagu to use a brand new character just for this series that he had no attachments to, or properly introduced the NTR/porn elements right from chapter 1. But it is the fact that this was sold as a initially shounen romcom, and sold side by side on the same bookshelf as Nagatoro or Dress-Up Darling, is what soured everyone.
The volume 3 sales being low is news to me, but also not surprising. It means that the Japanese audience also wasn't happy with the outcome and dropped the series.