Attack on Titan (Japanese: 進撃の巨人 Shingeki no Kyojin, lit. "Advancing Giants") is a Japanese manga series written and illustrated by Hajime Isayama. The series began in Kodansha's Bessatsu Shōnen Magazine on September 9, 2009. It is set in a world where humanity lives inside cities surrounded by enormous walls; a defense against the Titans, gigantic humanoids that eat humans seemingly without reason. The story initially centers on Eren Yeager, his adopted sister Mikasa Ackerman and childhood friend Armin Arlert, who joins the military to fight the Titans after their home town is invaded and Eren's mother is eaten.
A spin-off light novel series began in December 2011, and has received a manga adaptation. An additional light novel series and three additional spin-off manga series are also being serialized. A television anime adaptation produced by Wit Studio and Production I.G aired in Japan on MBS between April and September 2013 and a second season is confirmed to be released in 2016. Four video game adaptations developed by Nitroplus staffers in collaboration with Production I.G were announced to be released as bonus content for the third and sixth volumes of the Blu-ray Disc release of the anime, with another game developed by Spike Chunsoft for the Nintendo 3DS. A two-part live-action film adaptation, Attack on Titan and Attack on Titan: End of the World, was also produced by Toho and premiered in 2015. Attack on Titan and three spin-off manga are published in North America by Kodansha Comics USA, while the novels are published by Vertical. An anime adaptation of the Junior High spin-off manga, produced by Production I.G, began airing in October 2015. The anime has been licensed by Funimation Entertainment for North America, by Manga Entertainment for the UK, and by Madman Entertainment for Australasia.