Ok
In the novel Ruri tells him that she's a human (i can't remember why), but she doesn't yet show herself. After that when they're sleeping together he takes off her bracelet and finds out. If you want more spoils I can tell more (but mostly about the war bc that's what's coming next)
Could you spoil more haha?
So
Those rocks Asahi has are bombs made by killing fairies. And (if I remember correctly) the summoning magic was also possible bc of fairy killing. The dragon kingdom wins the war with rins and kotaros (the fairies) help. Also ruri gets to scratch the Nadarhias kings and high priests faces. Asahi and the other guys from the original world get brought to the dragon kindom. They use something to block Asahis charm magic so it won't work anymore. The other people from the original world apologise to Ruri (she doesn't forgive them). Also Asahi (and the other people) thought that this world was like a game and they could go home. Nope. Ruri shouts at Asahi finally silencing her and saying that she needs to get it together. After that Asahi and the other people are sent somewhere to live and work (idk where).
Then the part I don't really like:
Ruri finds her old phone and starts thinking about how to charge it. One of the fairies tells her that they know how. It turns out there where fairies in the original world as well. Ruris patents knew about this. Ruri gets to send a letter to her original world (with the help of Rin or Kotaro) and apparently her parents know how to go from one world to another. I'm not really sure about that last part but that's as far as I've read.
Oh... ew? That last part...
I suppose it can’t be that bad if it’s executed properly.. idk
Can anyone spoil me on whats going to happen next and how the king finds out abt Ruri?