This was a quite cute and amusing story, but the author made bad choices for the extra characters. His sister, for example, is a raging brocon hypocrite genius. Almost at the level of a yandere, she's sick in the head. Even though the mc and heroine is already married(kind of), she isn't giving up and tries to bend them apart forcefully with her hypocritcal actions and speeches. I've never liked this type of character and it's made far worse because she's getting in the way too much in this particular type of manga.
The thing is like this, you can have this type of character in a normal harem manga(or even non-harem if things just aren't decided yet and the mc isn't in a relationship yet). If things aren't decided yet. But the problem is that the heroine is already decided, there's no place for more girls. We're not reading this to see the mc build a harem and gradually get into a romantic relationship with them. He's already in a relationship with the heronie and it's final, so these pests are just obnoxious. If she were in a normal harem manga and vied for the top spot amongst the different girls, it'd be fine, but this isn't a harem manga in the first place, her existence is misplaced. She's attempting reverse-NTR and I'm not really fine with that shit unless the entire premise of the manga is to have many girls. You should know this before starting to read this.
However, even so, I think that this manga is worth reading for sure. Despite the side-cast being annoying at times, it's still a very cute and decently amusing story that I would never regret reading or feel like it's just a time killer that I'm reluctantly reading because I have nothing better at hand at the moment. Even for the side-character thing, I might be a bit too nit-picky about it and too defensive of their relationship. At the end of the day, it's all intended to be comedy, an attempt to make the reader laugh at their silliness. It's not as if she's going to succeed and it's nothing TRULY serious even if she's a sick freak.
Still, while not being a deal-breaker, it is a fact that it did bother me quite a bit while reading and reduce my overall enjoyment. That, coupled with the fact that the main purpose of people around him is to get in the way and make a nuisance of themselves to make sure he doesn't progress much in the relationship, truly does reduce the score by at least 2 points. I mean, these guys aren't doing it by mistake. They're trying their damn hardest at it even when it's none of their business, makes me wish this little god was a bit more malevolent and would slap their heads off at times, teaching them a lesson about not getting in the way. I truly wish they'd just die and be replaced by more decent characters that are actually funny, I guess the author's view on "amusing" is very different from my own. If there's something that grinds my wheels, it's busybodies who can't help but put their disgusting noses into other peoples' business and private lives. I might hate the busybody who are violently prying into their private issues even more than the unreasonable siscon. After all, that's the type of person that no one wants as their friend or even close to them as they make one uncomfortable. Doesn't make matters better that she just happens to like the mc romantically as well, why does the author keep introducing these pests all the time when the mc already has a wife? There's no place for them here...
I must say that I agree with ultenth's comment. He's completely right about it. It's just that I find it to be quite readable even so since I love both the main character and the heroine. If they weren't here, it'd be an instant 8/10 or even 9/10.
Oh, and one more issue I have with this manga is... What the heck is up with the heroine anyway? She's even weaker than normal people(13kg grip strength, can't do even one push-up, hardly any stamina at all, stuff like that) and she truly seems incapable of even defending herself without her powers. I don't know about you, but that doesn't seem godly at all to me. Sure, if she uses her powers and goes into "god mode", she instantly becomes OP(with restrictions), but why is her body so weak? Surely her specs should be higher than humans even without using her powers, not below them, she's even immortal, god dammit. Well, even WHEN she uses her powers, her body wasn't able to properly handle the "burden", thus she collapsed right after running a 50m dash in less than 5 seconds, just how weak is she actually if that amount of tiny "burden" from using her "powers" makes her pretty much faint away? She even gets colds like a normal human, what gives for a god to get afflicted by a minor human disease? Well, in the first place I guess that her personality and knowledge or rather lack of knowledge itself is the biggest issue, but I can accept that. It's not really a big deal as the focus of this story was never to create anything realistic, it's just a cutesy rom-com, nothing more.