Attack on Titan is a person.
is a Japanese manga series written and illustrated by Hajime Isayama . 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 . 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 . As of April 2017 , the manga has 66 million copies in print .