Gone, Then Returned

Human civilization is on the brink of extinction. Ming Anzai is forcibly brought by a Returner squad to the Night Sequence Institute, where she finds her mother, whom she thought had vanished into a parallel world ten years ago. Her mother asks her to join the Returner squad and make six jumps through time and space, reaching the point before this world overlaps with the ordinary world, and changing everything.

Everyone says the overlap between this world and the parallel world was caused by an accident during Ming Anzai's mother's experiment. They also say that, as the descendant of the culprit, Ming Anzai deserves to die a thousand deaths. After ten years of the world's "care," she should have been dead long ago. Yet she survived through her own ability and a tiny bit of luck.

And now they want someone who should have died long ago to save humanity?