Dreamcide

Ha-Jin Nam had always been plagued by nightmares, but one day, he dreams of an apocalyptical world seven years in the future where humans are fighting to survive among demons and zombies. Ha-Jin dismisses the dream as another nightmare until he finds out Yu-Ri Hong, the girl he had seen in his dream, has transferred into his school.... With his ability to switch back and forth between his school life and the oncoming apocalypse, will Ha-Jin be able to prevent what causes the world’s destruction?

(Source: Tapas, edited)