In a world 2000 years before present day, a young girl of the name Ymir Fritz made a deal with a spiritual existence known as the "Devil of All Earth", becoming the first ever titan shifter with granted abilities. With the power she was granted, her power was used by the King to strength the Eldian Empire and was used against the enemy nation, Marley, during the war. 13 years later, she died and her titan abilities were passed on down to 9 individual Eldians, into 9 different Titan forms. These titans were known as the Nine Titans by many. As these titans were created, mindless titans, also known as abberant titans were able to be created through the injection of the titan shifter's spinal fluids into people of the Eldian race. In the island of Eldia, the king, Karl Fritz had used the power of the Founding Titan to create the three walls, named after his daughters, Rose, Maria, and Sina. They were made to protect the citizens from abberant titans and from the enemy nation of Marley, who had already been able to seven of the nine titan shifters. One century later, a boy named Eren Yeager became curious to see what was outside of the walls and was determined to see the world outside. In the year 845, the outer wall of of Shiganshina District was breached by the Colossal Titan and the inner wall (Wall Maria) breached by the Armoured Titan. Having witnessed the death of his mother by an abberant titan, Eren declares his hatred for the titans and promises to kill off all of them. Within 5 years in 850, him and his friends Mikasa Ackerman and Armin Arlert join the training corps and later on join the Survey Corps where there are taken in by Squad Captain Levi Ackerman and Commander Erwin. With Eren discovering that he is a titan shifter himself, he vows to kill the Colossal and Armoured Titan and restore peace outside the walls.