A 100 years ago on an alternate world, giant humanoid creatures called Titans, suddenly appeared and nearly wiped out humanity, devouring them without remorse or reason and only targeting them, now resides within three enormous curtain walls the outermost is Wall Maria, the middle wall is Wall Rose and the innermost is Wall Sheena. humanity has lived in uneasy peace for one hundred years, many people growing up without ever having seen a Titan. This all changes when one day, a giant 200 ft tall colossus Titan mysteriously appears after a strike of lightning and breaches the outer wall (which is 50 meters tall) of the Shiganshina district, a town at Wall Maria, allowing the smaller Titans to invade the district forcing humankind to abandon the land between Wall Maria and Wall Rose, evacuating the remaining population into the inner districts. The sudden influx of population causes turmoil and famine. Combatting the Titans in the adventures of Eren Yeager, Mikasa Ackerman, and their childhood friend Armin Arlert who once lived in the town of Shinganshina. But when Wall Maria is breached by the Colossal Titan with the Armored Titan further compromising the town, chaos ensued as the Titans enter Shinganshina with a mass evacuation. Having watched in horror as a smiling Titan eats his mother, his father having mysteriously disappeared after giving him a key to their basement, Eren vowed to kill all the Titans and enlisted in the military with his friends following suit. the military, which is divided into three branches. Foremost in the story is the Survey Corps, which goes out into Titan territory to try to reclaim the land.