Claim: Attack on Titan has been adapted into a video game by Nitroplus.

is a Japanese manga series written and illustrated by Hajime Isayama . The series began in Kodansha 's Bessatsu Shōnen Magazine on September 9 , 2009 , and has been collected into 22 tankōbon volumes as of April 2017 . It is set in a world where humanity lives in 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 join the military to fight the Titans after their home town is invaded and Eren 's mother is eaten . However , as the story progresses and the truths about the Titans are slowly revealed to the reader , the narrative shifts to encompass Historia Reiss , squad leader Levi , Eren 's father Grisha , and other supporting characters .   The spin-off light novel series Before the Fall began in December 2011 and has received a manga adaptation . Two additional light novel series and four additional spin-off manga series have also been created . An anime television adaptation produced by Wit Studio and Production I.G aired in Japan on MBS between April and September 2013 and a second season of the series premiered in April 2017 . 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 , and a live-action web-series were released in 2015 . An anime adaptation of the Junior High spin-off manga , produced by Production I.G , began airing in October 2015 . Attack on Titan and all five spin-off manga are published in North America by Kodansha Comics USA , while the three novel series are published by Vertical . The anime has been licensed by Funimation for North America , by Manga Entertainment for the UK , and by Madman Entertainment for Australasia .   Attack on Titan has become a commercial success . As of April 2017 , the manga has 66 million copies in print . The release of the anime also saw a boost in the series ' popularity , with it having received widespread critical acclaim for its atmosphere and story . Although it also gained fame in neighboring Asian countries , the series ' themes have been a subject of controversy .