Blue Exorcist

The world of Blue Exorcist consists of two dimensions, attached to each other as a mirror and its reflection. The first is the material world where humans live, Assiah (物質界（アッシャー）, Asshā), and the other is Gehenna (虚無界（ゲヘナ）, Gehena), the world of demons, which is ruled by Satan. Originally, a journey between the worlds, or even a contact between them, was impossible, however, any demon is able to pass to the dimension of Assiah through the possession of a living being in it. Even so, demons have historically wandered among humans unnoticed, visible only to people who have had contact with demons before.

In contrast, there are Exorcists, people who train to destroy demons who act in a damaging manner in Assiah. With more than two thousand years of existence, this group has several branches all over the world being secretly under the command of the Vatican itself and acting in a clandestine manner.

Kazue Kato took inspiration from Terry Gilliam's The Brothers Grimm (2005), as she tried to work the angle of brothers fighting against monsters into a story. She eventually decided on making the story about demons and exorcists, thus conceiving Blue Exorcist. Due to exorcists being the main idea of the story, the manga features a lot of Biblical references. In an interview with Anime News Network, Kato said: "I should not run away from these references if I'm working in the Exorcist genre." An ending was planned by Kato but the exact length of the series has yet to be decided based on the manga's popularity in Japan.

In 2016, Kato stated, "I think there might be four more arcs. I have a rough storyline complete for the ending, but I haven't figured out all of the details. I have a few things where I'm not sure what to decide to do." In July 2021, Kato announced that the manga would enter on an eight-month hiatus to work on a six-chapter manga mini-series adaptation of Fuyumi Ono's Eizen Karukaya Kaiitan.

By November 2016, Blue Exorcist had over 15 million copies in circulation. By December 2022, the manga had over 25 million copies in circulation. The manga has been popular in Japan with the seventh volume receiving first print run of one million copies becoming the first Jump Square manga to reach such milestone. The release of the anime also drastically increased the manga's sales to the point that Shueisha decided to increase the print run for the seventh volume.

Critics have praised the Blue Exorcist manga, with Comic Book Bin reviewer Leroy Douresseaux feeling the first volume had potential, enjoying the comedy in the work and the characters and their interactions, recommending it to teen readers. Danica Davidson from Otaku USA felt that while the series employs disturbing storytelling, Rin's heroic traits despite being Satan's son make the plot more appealing to the readers. Kato's artwork has been praised by Anime News Network's Carlo Santos for the way each character has distinct traits while background images are well designed. Deb Aoki of About.com praised Kato's art and the series' "multi-dimensional world that melds European architecture, Japanese culture, modern technology and Tim Burton-esque whimsy", also stating that it is a "multicultural mishmash" of Harry Potter, Cirque du Soleil, Blade Runner and Alice in Wonderland, but she called the action scenes "a bit chaotic, and sometimes hard to follow".