The story centers around Eren Yeager and his friends Mikasa and Armin. 100 years ago, mankind was almost wiped out by giant humanoid creatures called Titans who devour humans. To defend themselves against the Titans, the surviving few forged massive walls and since then all of humanity has been enclosed within these walls. Peace and refuge was hard fought but it came at the expense of freedom. Generations of human kind thereafter never had a chance to venture beyond those giant walls and the existence of Titans gradually became a mere myth.