Fr fr I feel like I might die before I get answers ( ╥﹏╥)
I have a feeling it's kept as additional content (meaning it would be mentioned far later on) I'm curious if Reiko could be summoned (sometimes imagined her grandson summoning her due to some extreme complication or a fragment of her soul in some object) Even about Matoba's elder sister who doesn't like cats hasn't been brought up yet. I like this balance of light and heavy situations. Despite being slice of life, it has horror scenes and jumpscares.
On a side note, I like how it's non-romantic other than oogling fangirls of Natori, only uncomfortable part was how youkais & at times humans substitute MC for Reiko, which was uncomfortable whenever it came up. It was like MC was just a carbon copy of a dead person long gone... felt like skipping those parts, but without those, flashbacks of Reiko would be meaningless. Especially Hinoe, MC wouldn't get it as he's a pushover when it comes to dealing with someone emotionally, but he is just a fake Reiko for her. It's just sad that only some scenes are shown where he is himself, NOT Reiko.
Is been a years I been curious about who is Natsume grandfather..... why there's no more clues except for those two dragons chapter.