Yamibo: Darkness, the Hat, and the Travelers of the Books

Hatsumi Azuma disappears on the morning of her 16th birthday. Along with a feathered companion and a keeper of the Great Library named Lilith, Hatsumi’s adopted sister, Hazuki, goes world-hopping in search of her.

Hazuki meets Lilith and learns that she herself possesses the essence of the protector of the Great Library. Hazuki accepts Lilith's help traveling the worlds and Hazuki, Ken-chan and Lilith set off in search of the missing sister.

Ritsuko is serving the Princess Mariel. Mariel falls for the charms of Gargantua, now an alchemist. His attempt to sacrifice her is foiled by Ritsuko, but the princess is rendered half-demon and takes her own life.

Hazuki and Lilith reach a prehistoric world. Lilith is mistaken for a god. A cavegirl named Quill develops an attachment to Hazuki, offering herself up as a sacrifice. The real god appears but is defeated by Hazuki. The search is another dead end.

Hazuki and Lilith arrive on an island and meet a young girl, Milka, her white tiger, and the demoness Seiren. Milka does not age and suffers from "mindquakes" related to the Great Library.

Milka is saved by her white tiger. Arya reveals that Seiren was a demoness spawned by Lilith and that Seiren is only interested in harnessing Milka's power. A long flashback shows Hazuki and Hatsumi's life before the latter's disappearance.

Hazuki saves a fox spirit, Meilin, from a band of samurai in a feudal Japanese world. She encounters Princess Fuji, who looks identical to Hatsumi except that she speaks. Ninjas intent on gaining Princess Fuji's mysterious power attack the mansion.

A charged-up Hazuki rescues Princess Fuji. Meilin gets summoned to Gargantua's dimension because he thought she had the comb. In flashback, Lilith accepts Mariel’s soul from Gargantua in exchange for a world of his own.

Lilith and Hazuki arrive aboard a colonization spaceship where a computer is caring for a whole cohort of children. A habitable planet must be found soon for the survival of the children.

With Lilith’s help, the ship warps within reach of a suitable planet. The children land on the planet with the DNA samples of Earth's animals.

Gargantua, Hazuki and Lilith all argue over Jill/Hatsumi/Eve, who stops their bickering. She then tries to set things right. Gargantua finally realizes that it is Ritsuko that he loves.

Lilith lashes out at Eve for abandoning her for what seems to be tens of thousands of years and Eve tries to make it up to her. Lilith notices that Eve misses Hazuki, who seems not to have returned to the correct book-world.