With mankind desperate to find a way to survive, they went into hiding. Around them, all civilization was gathered into three 50-meter walls that helped keep the Titans out. In year 845, one 60-meter Titan broke through one of those walls, and from this point on it only got worse. An enterprising young man named Eren Jaegar vows to find a way to rid the world of the Titans and save mankind. He is joined by his sister Mikasa Ackerman and his best friend, Armin Arlert as they set out to save the human race without fail.