Humans and demons are two sides of the same coin, as are Assiah and Gehenna, their respective worlds. The only way to travel between the realms is by the means of possession, like in ghost stories. However, Satan, the ruler of Gehenna, cannot find a suitable host to possess and therefore, remains imprisoned in his world. In a desperate attempt to conquer Assiah, he sends his son instead, intending for him to eventually grow into a vessel capable of possession by the demon king. Ao no Exorcist follows Rin Okumura who appears to be an ordinary, somewhat troublesome teenager—that is until one day he is ambushed by demons. His world turns upside down when he discovers that he is in fact the very son of Satan and that his demon father wishes for him to return so they can conquer Assiah together. Not wanting to join the king of Gehenna, Rin decides to begin training to become an exorcist so that he can fight to defend Assiah alongside his brother Yukio. [Written by MAL Rewrite]

The ExWire of True Cross Academy are beset with shock and fear in the aftermath of discovering that one of their own classmates, Rin Okumura, is the son of Satan. But for the moment, they have more pressing concerns than that of Rin's parentage: the left eye of the Impure King, a powerful demon, has been stolen from the academy's Deep Keep. After an attempt is made to steal the right eye in Kyoto as well, Rin and the other ExWires are sent to investigate the mystery behind the Impure King and the ultimate goal of the thief. While this mission has them cooperating for the time being, Rin has never felt more distant from his fellow exorcists. In his attempt to reconcile with them, he undergoes specialized training to control his dark power. However, when the right eye is stolen not long after their arrival, the unthinkable threat of a traitor amongst them leaves them in need of all the power they can get. [Written by MAL Rewrite]

After an enthusiastic invitation from her friend, Kaede Honjou reluctantly agrees to try New World Online: a very popular VRMMO played by thousands of people across Japan. Naming her in-game character Maple, she sets out on her journey. As a complete novice to such games, she allocates all of her stat points into vitality, desiring to not get hurt. With not a single point in any other stat, Maple has extraordinarily high defense, but she can't move quickly or hit hard. This doesn't end badly for her, however. Due to her high defense, Maple acquires overpowered skills such as Total Defense, Poison Immunity, and Devour. These skills, along with the incredibly powerful items she obtains, allow her to obliterate most enemies in a single hit. After only a few days of playing the game, Maple claims third place in a server-wide event, gaining a reputation as a player who is both unkillable and absurdly powerful. Despite her overpowered character, Kaede has much to learn. As she progresses through the game, she meets new friends and acquaintances, helping her complete new levels and events. Through all of her adventures, she may even pick up some other crazy skills that exceed all expectations. [Written by MAL Rewrite]

Historically, 72% of all the deaths in London are related to dragons, fantastical beings invisible to the majority of the people. While unknown to most, some people have been standing up to these dragons. Only inhabitants of Reverse London who live in the hidden "reverse" side of London can see the dragons. Even then, only a selected few become qualified enough as witches or wizards to make direct contact with them. The protagonists of the story are witch duo Noel Niihashi and Ninny Spangcole. They are protection agents for Wing Bind (WB), an organization for dragon conservation and management. Their mission is to protect and manage the dragons within London on behalf of the people. (Source: Official Site)