A girl wakes up from a coma and immediately makes a deal with an alien that might kill her anyway. The show never explains why that's the right choice, because it isn't one, it's just the only move left. Every episode pulls the camera back to show you how many other people made the exact same impossible decision, and what it cost them to live with it.

Years ago, gates between dimensions opened across Earth, letting beings from five warring worlds, the Z/X, carry their conflict here. A treaty now holds a shaky ceasefire, and some people are forming pacts with the newcomers. For Azumi Kakamigahara, who has spent much of her life in a coma because of a disease, the choice is easy: bond with a beautiful Z/X named Rigel or die. The pact sends her to the newly founded Fujimisaki Academy, where teams of young women and their Z/X partners quietly train to meet the next wave of hostile invaders. Azumi and her new friends have barely arrived when the enemy strikes the school for the first time. The series is an adventure mixing fantasy and science fiction, based on the Z/X manga and collectible card game.