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]

After an awe-inspiring battle with Ichibei Hyousube—leader of the Soul Society's Royal Guard—the powerful Yhwach moves into the final stage of his master plan. He aims to slay the Soul King, the being whose very existence maintains the status quo of three worlds: Hueco Mundo, the Soul Society, and the realm of humans that Ichigo Kurosaki and his closest friends hail from. Conquering his own bout with the remainder of the Royal Guard, Uryuu Ishida joins Yhwach in his efforts to create a new world in his image. With a flood of resolution and newfound power, Ichigo rushes to stop Yhwach from accomplishing his ultimate goal and save the countless lives within the three existing realms. But Ichigo has a complicated lineage, one that leaves him susceptible to Yhwach's sinister influence. Meanwhile, in a final desperate gambit, Jirou Sakuranosuke Shunsui Kyouraku, the newly promoted head captain of the Soul Society's combat corps, enlists the help of an old enemy whose immense power may turn the tide of battle.

Long ago, the king of Orvelia, Kyle, defeated the demon king Angmund and brought peace to the world. However, one hundred years later, demons have been sighted in the forests, threatening humanity once more. A scouting expedition is sent to verify the claim but only one member returns. Meanwhile, Riheet, the leader of a dark elf mercenary group, plots to take over Orvelia to exact revenge against the humans who forsook their race a century ago. The knight apprentice Kasel, accompanied by the priestess Frey, sets out to rescue Clause, an old friend who went missing in the tragic mission. However, along the way, Kasel discovers that he is the son of the revered King Kyle and the only one who can wield the Holy Sword Aea—the same sword that slew the demon king. To fulfill this destiny, the young knight must embark on a perilous quest, unseal the sword, and end the fear instilled by demons. As Kasel's journey to bring hope to humanity and Riheet's vow for vengeance intertwine, what fate could possibly await them?

Second season of .