Borrowing a Ray of Sunlight

Red rain fell, and the world underwent a cataclysmic transformation, sweeping humanity into the torrent of a great disaster.

Faced with rampaging beasts and unknown invaders, the survivors struggled desperately to stay alive.

Yet beneath the shadow of this calamity, a conspiracy of unfathomable depth was slowly coming to light.

The female lead is universally adored. There may be a male lead, and there may be more than one.