The "Medicine Seller" is a deadly and mysterious master of the occult who travels across feudal Japan in search of malevolent spirits called "mononoke" to slay. When he locates one of these spirits, he cannot simply kill it; he must first learn its Form, its Truth, and its Reason in order to wield the mighty Exorcism Sword and fight against it. He must begin his strange exorcisms with intense psychological analysis and careful investigative work—an extremely dangerous step, as he must first confront and learn about the mononoke before he even has the means to defeat it. The Medicine Seller's journey leads him to an old-fashioned inn where Shino, a pregnant woman, has finally found a place to rest. The owner has reluctantly placed her in the last vacant room; however, as she settles in, it quickly becomes clear that the room is infested by a lethal band of mononoke, the Zashiki Warashi. With his hunter's intuition, the Medicine Seller begins his investigation to discover the Form, the Truth, and the Reason before the Zashiki Warashi can kill again. [Written by MAL Rewrite]

Mysteria Academy is a prestigious magic school that teaches magic without discrimination to the three factions (men, gods, demons), who usually are engaged in battle with each other. Two of the academy's students are Anne, a princess and honor student, and Grea, a princess born from a dragon and a human. (Source: ANN)

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]

Rikuo Nura, a part-youkai and part-human boy, grew up as the young master of the Nura Clan. Comprising youkai of all shapes and sizes, Rikuo treated the clan like family, however, he learned that he was the only one among his classmates who saw them in this light. To most, they were terrifying creatures of folklore who ate children and relished in bloodshed. Taking this to heart, he swore to live his life as a normal human. Normalcy, however, is hard to come by for young Rikuo. Complicating his goal are his youkai attendant, who under the name Tsurara Oikawa, goes to school alongside him; the young onmyouji Yura Keikain; and his close friend Kiyotsugu, who idolizes youkai and hopes to prove their existence. To make matters worse, rival youkai and other entities threaten to harm those Rikuo holds dear. If he wants to protect what's important to him, Rikuo must acknowledge his ancestry—that he is the grandson of the legendary Nurarihyon—and transform at night into a youkai, becoming worthy of being the next leader of the Nura Clan. [Written by MAL Rewrite]