Season 1

Attack on Titan is set in a world where humanity is on the brink of extinction due to the emergence of giant humanoid creatures known as Titans, who devour humans without any apparent reason.

The story follows Eren Yeager, his foster sister Mikasa Ackerman, and their friend Armin Arlert as they join the military in order to fight the Titans and protect humanity. Along the way, they encounter new allies and enemies, as well as secrets about the Titans and the world they live in.

Season 1 begins with the fall of Wall Maria, the outermost barrier of humanity's territory. The Titans breach the wall, and Eren witnesses his mother being eaten alive by one of them. This traumatic event motivates Eren to become a soldier and seek revenge against the Titans.

Throughout the season, Eren and his friends face various challenges as they train to become soldiers and fight against the Titans. They uncover the existence of a mysterious female Titan who seems to have intelligence and is targeting Eren specifically. They also learn that there are humans who can transform into Titans, and that there may be a way to seal the wall breaches and prevent further Titan attacks.

The season ends with the revelation that the Titans are actually humans who have been transformed through a mysterious process. The female Titan is captured, but the discovery of a traitor within the military leaves the characters and the audience uncertain of what is to come.