NPCs' 'deploy me too' requests

[Mirinee]

I managed to find a guide which showed me the storyline branches and which had cutscenes.

It means there's a cutscene associated with deploying both characters together, or there's a card available if you play with that character and talk to them later. In some cases both apply.

I understood your examples, but I don't understand the first condition you stated. What do you mean by "both characters together"? Is it obvious? I feel a bit stupid now.

P.S. Yep. Companion card good unless your opponent also uses it on you.