"Attack on Titan: Chronicle" is a compilation film that condenses the events of the first three seasons of the anime series "Attack on Titan" into a single narrative. The story is set in a world where humanity resides within enormous walled cities to protect themselves from the Titans, gigantic humanoid creatures that devour humans without reason. The walls have stood for over a century, but their peace is shattered when a colossal Titan breaches the outermost wall, leading to widespread destruction and chaos.

The protagonist, Eren Yeager, witnesses the death of his mother during the attack and vows to eradicate all Titans. Alongside his adoptive sister Mikasa Ackerman and their friend Armin Arlert, Eren joins the military to fight against the Titans. The narrative explores their growth as soldiers, the harsh realities of war, and the moral complexities of survival. Eren discovers he possesses the ability to transform into a Titan, a power that becomes both a weapon and a source of conflict as humanity grapples with its implications.

As the story progresses, the focus shifts from the external threat of the Titans to the internal struggles within human society. The Survey Corps, a military branch dedicated to exploring beyond the walls, uncovers dark secrets about the origins of the Titans and the true nature of their world. Key revelations include the existence of intelligent Titans, the political machinations within the walls, and the revelation that some humans can transform into Titans. Characters like Commander Erwin Smith, Captain Levi, and Historia Reiss play pivotal roles in unraveling these mysteries and shaping the course of the conflict.

The narrative delves into themes of freedom, sacrifice, and the cost of survival, as the characters confront increasingly complex moral dilemmas. The line between hero and villain blurs as alliances shift and the true enemy becomes ambiguous. By the end of the chronicle, the story sets the stage for the final conflict, where the fate of humanity and the Titans hangs in the balance. The film serves as a comprehensive recap for viewers, providing a cohesive overview of the intricate plot and character arcs that define the series.