In the wake of Eren Yeager's cataclysmic actions, his friends and former enemies form an alliance against his genocidal rampage. Though once bitter foes, Armin Arlert, Mikasa Ackerman, and the remaining members of the Scout Regiment join forces with Reiner Braun and the survivors of the Marleyan military. Their meager united front sets out on a mission to stop Eren's wrath and—if possible—save their old comrade in the process. As Eren pushes forward at any cost, he battles his own internal turmoil. Although he feels immense remorse over his horrific invasion, Eren believes he harbors noble intentions: he believes the path ahead is the only way to save his friends and, to a greater extent, his people. The opposing battalions spiral toward an inevitable final clash that may claim the lives of millions. Though they face an army of monsters beyond anything they could have previously imagined, Mikasa, Armin, and their allies stand brave in the face of certain doom.

Recap of leading up to the seventh season.

Segua Kingdom has been losing the war against Ninterdo Empire but the tables are turned by the appearance of a boy called Gear. All the characters are parodies of Nintendo or Sega games such as Sonic the Hedgehog, Super Mario Bros., The Legend of Zelda etc.

Long ago, the gate to the world of darkness was sealed. Now evil warriors, known as Remnants, are trying to reopen the gate and let demons take over the world. However, at Tobira High School, there exist guardians of the gate who must risk their lives to prevent the gate from being opened.