I'm assuming the 'talk' she wanted to have with him was about that shiki the family had lost and she might have wanted his help with it as someone who wasn't affiliated with the Matoba clan?? But then she didn't end up saying anything because she realized Matoba was at the meeting and she didn't want him to know.

Someone in her position would have definitely known about Natori slowly making a name for himself and picking up random jobs to prove his skills. Matoba himself might have told her about it. She doesn't disagree when Natori says he assumes Matoba had negative things to say about him because knowing Matoba, he probably complained about Natori wasting his talents or something. And I don't know if I'm giving baby Seiji too much credit when I say that he might have done it on purpose. Setting his pieces on the board, so to speak.

But directly involving a Natori in the Matoba clan's affairs is certainly an interesting move. Maybe Nanase felt like she couldn't go to the main clan for help for some reason, or maybe she was hoping to resolve this issue without involving them. And in true Matoba Seiji fashion, it looks like he first tried to help from behind the scenes, concealing his involvement, and only intervened directly once it became clear Natori got himself cursed.

You have to understand. I spent the majority of my first Natsume Yuujinchou read through believing that Natori was in his thirties. That whole time I was reading Natori and Natsume's relationship as "cynical experienced mentor and his kind, optimistic mentee that is slowly softening his edges" only to then find out that Natori is fucking 23.

He's college aged! No wonder he's a fucking mess, he should be at the club! (He would hate the club).

And suddenly my third eye opened as I realized "Oh my God- they're literally the Tumblr post"

One of the main reasons she stays by his side is because she sees herself as the guardian of flame alchemy. She’s trying to make sure of two things: 1. no one ever gets their hands on it again. and 2. the only person who can use it never misuses it again. That’s why she follows him. She has to. She’s watching the weapon she helped create.

And she has to keep him alive not only because he’s the one with the political power (meaning he’s her only real way to make sure the trials happen), but because he has to live long enough to atone for what he did with flame alchemy. The power SHE gave him.

From Riza’s point of view, every crime Mustang commits is hers too. Every time flame alchemy is used to kill that blood is on her hands too. Every person he killed is someone she killed by proxy.

She’s not just guarding him. She’s sharing his guilt. It’s like she’s trying to atone for her own sins, but he has to atone too so she can atone through him.

Natsume: It seems that another small mirror was hidden behind the mirror. Natori: ….