The author's introduction is incompetent, so just make do with it.
Literary Edition: What will you do when the world becomes something you are unfamiliar with? Should we choose to die quietly or live strong?
What do you do when your best friend turns into a monster? Should we choose to abandon or protect?
What do you do when you have to choose between friendship and love? Choose to give up or choose. . .
Relaxed version: Sit back and watch a few girls' journey of fighting (resting) monsters (raising) and upgrading (reviving) levels in the end of the world.