Myriad Colors Phantom World

In the near future, monstrous creatures called “phantoms” descend upon the world. Haruhiko Ichijo is a student at Hosea Academy, along with Mai Kawakami, Reina Izumi, and Koito Minase, three girls who fight these creatures. High school life proceeds as normal until a certain incident reveals the truth of their world to them.

(Source: Crunchyroll)