It's the year 3016. Earth, is now no longer inhabitable. Creatures roam our common grounds with teeth only made in causing human despair. All around us humanity diminishes from our eyes, our loved ones just plucked out of our grasps. These creatures are what we call Titans. They range in various shapes and sizes, a variety of abilities for each, but all hold the same hunger of human destruction. Thankfully, humanity has managed to move them to a more…safer place. They planned themselves out with one group remaining on Earth behind a gate. Within that gate would be two others leading to alternate dimensions, or just another planet. In total three gates would exist in the world, but all of humanity hoped that one day they would find a new planet or home to repopulate, or at least take their home back from the Titans.
In the underground, a world where the first gate reveals itself to be Gate Maria; the first population of humanity stands. The quality of life there is poor, humans fight each other for survival, the protection there is minimal and there are barely any doctors in sight. Their technology though is considered average, the only high tech gear they were all given were a wrist watch and code at birth. This watch holds many essential things in life such as contact information, and announcements from within Gate Sina. Within the gate there are two other portals in the center; the second gate, called Gate Rose, leads to another dimension of average living, advanced technology, and safety measures. There the population is slightly smaller than in Maria, but the living conditions are much better. Lastly, the third gate, named Gate Sina, leads to a world populated by various mythical creatures, luckily the humans made peace, but there is always a group going against them. The living standards are fabulous. The technology which could blow many minds of what it could do, the only downside was the safety. Out of all three gates the wisest choice would be to live within Gate Rose, but within the last century creatures much like Titans appeared. They stood at 4 meters tall, taking down a few villages, but luckily a wall was built around them to ensure no more destruction.
Within that century, various gates appeared leading to new planets, new environments, new discoveries yet to be made, but it came with a consequence. Creatures flocked in and out from these gates killing, kidnapping, and maiming the humans. Finally, after discussion with the central government within Gate Sina, the officers have agreed to create three factions. The first one being the military police, their main goal is to keep the civilians in check, and to stop any disputes happening with people and creatures alike. The second one being the garrison, their main goal is to keep watch over the gates to ensure no intruders as well as keeping the gates in check, not only that, but they are to remain stationed at all gates within Maria, Rose, and Sina. They were to keep anything from coming in, or out unless having certain authorization from commanders. The last group is the recon corps, not many were happy with it, but it would help humanity in understanding their current crisis. These people would collect data of all the various creatures in each gate, not only that they carried the burden of exterminating all threats to humanity, including the titans.
All three of these roads ensure the protection, and safety of the humans within each territory. The only problem was, the immense years of training. Each rookie had to have at least five years of training with the various forms of 3DMG, or 3D maneuver gear, each one being specified for a certain creature in a designated gate. Not only that, but the information of how to exterminate the pests.
But really, the story begins with a 8 year old boy by the name of Eren Jaeger who lives within Gate Maria, and the terror he had to witness the day humanity lost one of it's gates.