Iruma Ikaruga is living his best high-school life ... until mascot-looking aliens from another world invade with their flesh-eating bugs, seemingly hell-bent on destroying humanity violently and effectively! On that fateful day, Iruma loses everything ... his normal life, his best friend, and his crush ... until six months later, when he catches a glimpse of her again. Is all hope for humanity—or just Iruma himself—truly lost?