Gekka no Hazure Gedou

In a world where humanity lives under the shadow of Gedou—murderous crow monsters born from corrupted humans—people have adapted to a fragile peace by restricting their lives to daylight hours, when these creatures remain dormant. Shiramine Miroku, a self-centered young man, lives with his little sister Hifumi and their mother, spending his days complaining about mundane responsibilities. His carefree existence is shattered when a reckless mistake unleashes a terrifying power that transforms both his and his sister's destinies forever. Now caught between two worlds, Miroku finds himself allied with the Rikudou, an organization dedicated to fighting the Gedou threat. As he struggles to protect what remains of his family, he must navigate the dangerous balance between his newfound nature and his desperate hope to save his sister from a fate worse than death. (Source: MangaHelpers)