Takashi Natsume has grown accustomed to his encounters with youkai through the Book of Friends, which contains the names of youkai whom his grandmother, Reiko Natsume, has sealed in contracts. These encounters allow Natsume to better understand the youkai, Reiko, and himself. 

The Book of Friends is a powerful tool that can be used to control youkai; it is sought after by both youkai and exorcists alike. Natsume just wants to live out his daily life in peace but is constantly disrupted by these experiences. If he is to end this torment, Natsume must explore more about the book and the world of exorcism, as well as begin to open his heart to those who can help him.

[Written by MAL Rewrite]

Rentt Faina, a 25-year-old adventurer, has been hacking away at monsters for a decade. Without much talent for the job, Rentt finds himself stuck hunting slimes and goblins for meager amounts of coin every day. Little does he know, all this is about to change when he comes across a seemingly undiscovered path in the Water Moon Dungeon. What awaits him at the end of the path, however, is neither treasure nor riches, but a legendary dragon that wastes no time swallowing him whole! Waking up a short time later, Rentt finds himself not quite dead, but not very alive either―He is nothing more than a pile of bones! Armed with nothing but his trusty sword, tool belt, and ghoulish new looks, Rentt sets off on his quest as a newly reborn skeleton to achieve Existential Evolution, hoping to one day return to civilization with a more human form. Will Rentt succeed, or will the dungeon consume him for the rest of his un-death...?

Fate Graphite is one of the forsaken. Cursed with the skill "Gluttony," he is ever starving, never sated... until the day he kills a dying thief and devours the man's strength—and his soul. The true hunger of Fate's Gluttony has awakened, and if he can learn to control his power, he will at last be the master of his own destiny.

After the events of the 1st series, Fenarinarsa continues to drift from Earth, so the King asks for help from the kingdom, Marinarsa, to send their daughter, Momo (Who is identical to the 1st one) to Earth to regain humanity's faith in their dreams.