Story (No Spoilers)

Attack on Titan centers around Eren Yeager a child, at first, living with his mother, his father, and his adoptive sister, Mikasa. They live in the Shiganshina District, a section of Wall Maria that is farther out then the actual wall. Everything is peaceful until the Titan's attack on his home city, forcing everyone to abandon that part of Wall Maria and move inwards for the Titans to claim the area between Wall Maria and Wall Rose for themselves.

Story (In-Depth)

|WARNING| The following information contains spoilers pertaining to the story/plot of Attack on Titan. If you are going to read the manga or watch the anime, it's highly recommended you find this information on your own.

Attack on Titan features a range of characters including antagonists, the Titans. Titans are giant humanoid creatures ranging from 3 meters tall to 15 meters tall that eat humans, it is known that they feast on mankind without reason due to their survival in a human-free environment for 100 years without touching any of the other sources of food in the wild. It is also known that they need sulight to be active, which explains why they are so docile at night. The 100 year peace ends when a Collosus Titan (60 m, 200 ft) breaches the wall seperating the Shiganshina District from Titan Country, letting the Titans outside the walls walk freely past mankind's defenses, killing hundreds lucky enough to find themselves trapped by the Titans, including Carla Yeager, the mother of our protagonist. The story of Attack on Titan centers around Eren Yeager, an emotional, but impulsive child struggling to find independence to be able to leave the walls. His life changes on the day of the attack when his mother is taken from him by a Titan, who split her in half and ate both the parts, splattering her blood all throughout the afternooon sky. This attack resulted in Shiganshina being lost to the Titans.

A few hours have passed and everyone thinks the Titan attack is over, everyone, including Eren, Mikasa, and their friend Armin, is being shipped on boats to the inner walls when the "Armored Titan", called that for the armor on its body, sprints at the wall between the already lost Shiganshina District and Wall Maria, breaking it down immediately. This forces mankind to also abandon the extensive space between Wall Maria and Wall Rose. Once older, Eren, Mikasa, and Armin join the military and after extensive training, Mikasa and Eren come out as some of the Top 5 recruits, the only portion of the recruits that can join the Military Police. Unlike everyone else, Eren wants to join the Scouting Regiment and, Mikasa being his protective, adoptive sister, follows his decision but before they can choose what part of the military they can join, they first are sent to protect the Trost District. Little did they know that 15 m Titans, were going to be the least of their worries at the time. Soon after the recruits arrived, the Collosus Titan appeared out of thin air, kicking a hole in the wall between Wall Maria and the Trost District. Eren, with his wish of avenging his mother and ridding the world of all the Titans, instinctively, attacks the Titan, triggering its ability to "superheat" its body, causing it to eject steam hot enough to burn Eren alive. This causes Eren to back away only so that when the steam clears, the Titan has disappeared. This breach in the wall causes Titans to flood in, killing a lot of the civillians and also a number of soldiers. The soldiers try to fight back due to their shortage on fuel but theres just too many, even for Eren. At one point, Eren is flying around the city on his 3D maneuvering gear when a Titan slaps his leg in mid-air. Taking it clean off. He lands close to a Titan which sees him and is about to eat him, but a closeby Armin won't let that happen. He quickly maneuvers over saving Eren from the Titan's grasp but putting him in danger instead. The Titan soon realizes this and grabs Armin, throwing him down the Titan's throat. All hope is lost for Armin until Eren's hand grasps Armin's, pulling him out. Eren is about to come out of the Titan's mouth when it chomps down, chopping Eren's outstretched arm clean off.

All hope is lost for Eren at this point including the hope that Mikasa had for him. Mikasa chooses that life without Eren isn't life at all so her solution is to remain calm as a Titan eats her. She is about to carry out this plan when a giant muscular Titan appears from behind her, ignoring Mikasa and attacking and killing the other Titan. Mikasa is now very confused and surprised, assuming that it'd be best to tell the others of the Titan's intentions, of its desire to kill other Titans. So the soldiers figure it'd be good to lure the Titan into killing the hostile ones guarding the Fuel Station, they manage to do this sucessfully until the Titan is weakened by many other Titans who were attempting to eat him.The Titan falls only to expose Eren who was half-conscious in the nape of the Rogue Titan's neck. This introduces the existence of Titan Shifters, a group of humans that can transform into Titans at will. The change happens when the Titan Shifter is hurt enough to produce blood, with a certain goal in mind. Some of the Titan Shifters include Annie Leonhart, a fellow recruit among the ranks of Eren and Mikasa. She is the Female Titan. A Titan that during the 57th expedition into Titan Country, took out many of the soldiers, not to eat them, but to kill them. She didn't care for eating them. She summoned other Titans to finish them off. The Armored Titan is Reiner Braun, also another recruit among the ranks of Eren, Mikasa, and Annie. The Collosus Titan is Bertolt Hoover, another recruit among the ranks of Eren, Mikasa, Annie, and Reiner. There is one Titan, however, that doesn't appear very large at all, she is actually very small but can take out larger Titans with her speed. Her name is Ymir and she was also a recruit but before that, she spent 60 years outside Wall Maria as her Titan form, proving that Titan Shifters do not age when in their Titan forms.