For many years humanity has fought against Titans—enormous beings who do not possess much intelligence, yet eat people and derive pleasure from it. After a prolonged struggle, the remnants of humanity built a tall wall surrounding the country of humanity, through which Titans could not pass. Since then, a century has passed and people live peacefully under the protection of the wall. But one day, teenagers Eren and Mikasa witness a terrifying event: a section of the wall is destroyed by a super-titan that appeared out of the air. Titans attack the city, and in horror they see one of the monsters devour Eren's mother alive. The boy swears that he will kill all Titans and avenge humanity.