Blue Exorcist

Blue Exorcist (Japanese: 青の祓魔師, Hepburn: Ao no Ekusoshisuto) is a Japanese supernatural action anime series based upon the manga of the same name created by Kazue Kato. The anime was created by A-1 Pictures of Black Butler and Fairy Tail fame and spawned two seasons. Season 1 aired from April 17, 2011 to October 2 of the same year in Japan. The original premiere date was April 10, 2011, but it was unfortunately delayed a week due to the 2011 Tohoku Earthquake and Tsunami. The second season, with the subtitle Kyoto Saga, was aired from January 6 to March 24, 2017. Three direct-to-DVD specials have also been released; the first being released on the fifth DVD/Blu-ray volume (along with Episodes 12 and 13 of the first season) on October 26, 2011, the second bundled with a limited pressing of the 19th manga volume on April 4, 2017, and a third set for an October 4 release date with the 20th manga volume. A feature film was greenlit on September 30, 2011 and released on Christmas 2012 in Japan. The English dub was streamed to Hulu weekly from October 2, 2012 to March 23, 2013, and the first special on July 9, 2013, included in the Season 1, Part 1 DVD/Blu-ray sets along with the first 12 episodes.

The franchise has been well received by fans, and the anime helped to significantly increase sales of the manga. Anime and manga critics compared the franchise with other shonen series, but praised its story and art.

Plot
Blue Exorcist centers around Rin Okumura, who learns that he and his twin brother Yukio are the half-blood sons of Satan and a human woman. When their adoptive father Shiro Fujimoto dies protecting Rin from Satan, Rin attends True Cross Academy to become an exorcist and defeat his biological father... under the teachings of Yukio.

Why it rocks

 * 1) The art style is AMAZING, especially the blue flames emitted by Rin and Satan. It reflects what a modern cartoon or anime should look like, and surprisingly, it gets even better in the movie and the second season.
 * 2) The music is awesome and greatly reflects the moods of each scene the music cues come on. It was composed by none other than Hiroyuki Sawano (Attack on Titan, Kill La Kill, The Seven Deadly Sins), who is a living legend in the world of music.
 * 3) All three intro themes [uverWORLD's Core Pride (Eps. 1-12 and first special) and Itteki no Eikyo (Eps. 26-37, Specials 2-3), and ROOKIEZ is PUNK'D's In My World (Eps. 13-25)] and all three outro themes [2PM's Take Off (Eps. 1-12, Special 1), Meisa Kuroki's Wired Life (Eps. 13-25), and Rin Akatsuki's Kono te de (Eps. 26-37, Specials 2-3)] are masterfully performed. A little bit of trivia: the first outro theme marked the Japanese debut of South Korean boy band 2PM.
 * 4) The voice acting is an auditory treat in not only Japanese, but also in its English, French, German, and Korean dubs as well. It feels like every single casting choice was handpicked by Kato herself. They're that good.
 * 5) This was the show that let then-relatively-unknown voice actors Nobuhiko Okamoto and Bryce Papenbrook, who both voiced Rin, rise to stardom. Most fans of these actors agree that Rin was their best role to date.
 * 6) It's very well written. The story is so suspenseful that waiting for the next episode or even season seems like an eternity, and the characters feel like they were based on real people.
 * 7) Mephisto Pheles's motives can be a little shady and serves as the franchise's token neutral character. He doesn't hate Rin like most Exorcists do, but doesn't fully trust him either. He's the mediator between the two.
 * 8) Rin is one of the most lovable heroes in fiction. Instead of just wanting to avenge his adoptive father, the one person he has loved and respected his entire life, he even risks his own life defending what he thinks is the right thing. Yukio provides him a necessary foil, as he is more studious and knows how to keep a leash on Rin to prevent him from doing something rash. Anyone who has siblings can relate to them.
 * 9) Some episodes have emotional appeal, like when some other True Cross students distrusted Rin simply for his half-blood status, and Igor's vendetta, where he first attacked Rin and later revealed that his family was killed by Satan, and when he resurrected his dead wife to exact his revenge a second time.
 * 10) The action sequences were beautifully choreographed. One might think the characters were rotoscoped from real actors enacting these sequences.

Bad Qualities

 * 1) The first season seems to lower in quality by the conclusion. Keep in mind that, while this anime was produced, the manga was still ongoing, so at around the seventeenth episode, the story deviates from the manga's and leads to an anime-exclusive ending.
 * 2) Amaimon can be an annoying antagonist at times.
 * 3) Even one of the greatest heroes of all time has bad qualities: Rin has a little too much fatherly love in his heart and isn't the sharpest tool in the drawer.