Wow, people complaining about an 18 & 24 y/o for 7 pages.

No wonder the world is going down the road of Japan birth rate decline if you have to be born the same week as your love interest for social acceptance.
This manga is alright but doesn't really have a lot going for it. It could have easily leaned more heavily into the grooming-your-protege aspect by making FMC a third year middle schooler and filling the series with ecchi. This series is overall pretty bland except for the government workers being set up as the antagonists. But I bet Kirito will surprise you and overcome all odds!
Seems like their complaint isn't them getting together, it's them getting together right now as, like they said, we're dealing with someone who should still be in high school and someone who normally would be a new office worker and in actuality is a long-term veteran in his field. I don't know about the claims of pedophilia, but I can see both sides as far as their relative stations. To put it frankly, she's not yet in a position to take care of herself. He could take care of himself easily even if he didn't have half Japan's GDP in his bank account, but she's still just made it to the sort of level you'd expect high school students and early college students to be. That is, I'd guess she's able to make about as much as you'd get in a generous part-time job, and she's still extremely new to taking care of herself. If they were to start dating now and get married, she'd be completely dependent on him. Setting aside questions of whether 18 is "adult" or not, she needs to reach a point where she's at least able to live independently if she chose, even if she never does.
I'm still just hoping we get a little more on the Kaori issue honestly, I know I'm just dragging this up for no reason but still. Ideally, I'd have Katsuki find out that Kaori was fired, hear why the boss fired her, and flip out realizing her very job was dependent on Reito. He'd reveal his paycut and dump her because there's no way he can support himself AND her on such low income. He'd probably even blame it all on Kaori, maybe telling her how wealthy and influential Reito is or maybe leaving her all the more confused. Without a job or a fiance, she has nowhere to turn and starts desperately searching for some way to support herself. At that point could have her see Reito again, or meet with her friend who introduced them, or somehow come across Karen and learn of her connection to Reito. Any such situation would be the perfect setup for her to finally find out the whole truth, how filthy rich Reito is, how far Adventuring is from her image of bottom-feeding bums, how very much of Reito's work had been for the specific purpose of giving her a happy, peaceful future. Apology would be inevitable there, as well as her going into adventuring herself. And then she could seek his advice for teachers, maybe end up studying under his former comrade just like Karen. Wouldn't be easy, like Maria I can't see a friend of Reito's showing any restraint or mercy toward her, but frankly she'd probably need a Spartan treatment as much as she deserves it.