Attack on Titan

Attack on Titan begins in a world where humanity survived near-extinction by retreating behind enormous walls built to keep Titans out. For more than a century, the city sees no Titans at all, but that peace ends when a colossal Titan suddenly breaches the defenses. Eren Yeager and his foster sister Mikasa Ackerman witness smaller Titans flooding into the city and Eren's mother being eaten. The disaster leaves Eren determined to destroy every Titan and take revenge for humanity.