Attack on Titan is a Japanese manga series written and illustrated by Hajime Isayama. Set in a world where humanity lives inside cities surrounded by enormous walls due to the Titans, gigantic humanoid creatures who devour humans seemingly without reason, the story centers around Eren Yaeger, his foster sister Mikasa Ackerman, and their friend Armin Arlert, whose lives are changed forever after the appearance of a Colossal Titan brings about the destruction of their home town and the death of Eren's mother. Vowing revenge and to reclaim the world from the Titans, Eren, Mikasa and Armin join the Survey Corps, an elite group of soldiers who fight Titans outside the walls.
The series began serialization in Kodansha's monthly publication Bessatsu Shōnen Magazine in its September 2009 issue. The first tankōbon volume was released in March 2010, and as of December 2016, twenty-one volumes have been released. In North America, the series is published in English by Kodansha Comics USA, that first published the first volume on June 19, 2012, with a three- or four-month interval between each release until mid 2013, when subsequent volumes started being released on a monthly basis to catch up faster with the original Japanese releases. The series has also been adapted into an anime by Production I.G's Wit Studio, with the first episode airing on April 7, 2013, on MBS. The anime is also being streamed by both Funimation and Crunchyroll on their respective websites.
Chapters in the Kodansha USA publications are numbered as episodes.
Attack on Titan: Junior High (進撃!巨人中学校 Shingeki! Kyojin Chūgakkō) is a parody manga written and illustrated by Saki Nakagawa, serialized in Bessatsu Shōnen Magazine since its May 2012 issue. The first tankōbon volume was released April 9, 2013, and as of December 9, 2015, 9 volumes have been released. In North America, the series has been licensed in English by Kodansha Comics USA, who published the first volume on March 11, 2014.