Noah’s Ark was actually a book meant to confine lost souls, called Animas, that spread evil.

Noah’s Ark was, in fact, a book meant to confine lost souls known as "Animas" that spread evil throughout the world. When the book was opened, evil ran free across the face of the earth… In this manga, Toah sets out with his faithful follower J, who resembles a puffed-up pigeon, to capture the Animas and lock them back up inside the Ark. But in truth, his main goal is to free his twin sister, his only surviving relative, from the Animas’ clutches.
Ongoing series