100 years ago, cannibalistic Titans appeared and devoured all humans in their way. The remaining humans then barricaded themselves in three gigantic walls for safety. Everything eventually changed when the Colossal and Armored Titans breached the outer wall, letting all the Titans in. All hope for humanity's survival now lies in the hands of Eren Yeager and the brave Survey Corps as they are the only ones capable of fighting the Titans, and knowing their secrets.