Monsters descended upon the humans all of a sudden, monsters that can't be detected by most, unless they have a strong sense. An invisible predator, it feasts on humans to grow in strength and powers. 4 Death Gods are chosen to destroy these monsters and to seal the "sink" hiding the monsters fast. The Doujinshi & Manga Lexicon [Vol. 1](https://www.doujinshi.org/book/410680/DEATH-GOD4(1)/) [Vol. 2](https://www.doujinshi.org/book/410681/DEATH-GOD4(2)/)