My Everyday High School Romance Could Never Turn into an Infinite-Loop Game

On the night before the story began, Hachiman Hikigaya unexpectedly gained the memories of an Earthling's entire life.

He never expected the Reincarnation Space to suddenly descend, proclaiming that the world was about to change and humanity might go extinct.

And so the protagonist began his journey through reincarnation, growing stronger and saving the world.

(The original story's timeline may be adjusted to suit the plot.)