Naruto Shippuden

Naruto Uzumaki is a young boy who has the Nine-Tailed Demon Fox sealed within him. Twelve years before the start of the series, the Nine-Tailed Demon Fox attacked the ninja village Konohagakure, slaughtering many people. In response, the leader of Konohagakure and its ninja military – the Fourth Hokage – sacrificed his life to seal the demon inside Naruto when he was a newborn. Konohagakure, however, regarded Naruto as if he were the demon fox itself and mistreated him throughout most of his childhood. A decree made by the Third Hokage, who replaced the Fourth Hokage after his death, forbade anyone mention the attack of the demon fox to anyone else. This included Naruto, who was not aware of the demon inside of him.