Shingeki no Kyojin

Humanity survives behind enormous walls after giants nearly wipe out the population. The giants are several stories tall, appear to lack intelligence, and devour people seemingly for pleasure rather than sustenance. After more than a century without a giant appearing, teenage Eren and his foster sister Mikasa witness a colossal giant suddenly destroy the city’s wall. Smaller giants pour inside, and the siblings watch as their mother is eaten. Eren vows to kill every giant and avenge humanity.