[The first he thinks of is the belief in death in itself. That is not a surprising thing: it's a concept that encompasses worlds and cultures, the one constant in everything and everyone. He would not be surprised at all to learn that Death is someone that is desired to be summoned.

...He doesn't like the idea that someone would wish for Death so fervently he would take on a physical form into this world, either. What kind of awful circumstances would cause one to desire such a thing?

Then again -]

Don't you wish for your own death, Fandaniel-san? I wouldn't be surprised if someone like you also existed in my world. But I don't know who would want 'Ryoji Mochizuki.' Nobody knew me when I first showed up.

[Kotone comes into mind - someone who is familiar and yet unfamiliar to him. Did she summon him? He doesn't want to suspect her, not when she has always been his closest confidant, but it is the only conclusion that he could think of.]

...There might be someone, but she never knew me before. I'm not so sure.

[Sure enough, as testament that he isn't a normal teenager, Ryoji isn't having any problems wrapping his head around all of these esoteric concepts. He's always been a sponge when it comes to new things, after all.]

I don't know how magic works in my world. I...think it exists? What I can do is clearly that. But I don't know if anyone there can actually use magic -

[Wait. There is someone! Ryoji's eyes widen in realization.]

Koromaru-san! Minato's dog can use magic!