A legend. That's all people thought it was. They never thought any more of it. Have you ever heard of the legend of the 'Protector of Konoha'? It is a legend depicting a spirit or otherworldy being that lives in Konoha and protects it until its last breath. No one has ever seen the being besides 1 person. Minato Namik...
-----The tailed beasts (尾獣, bijū), sometimes referred to as "Chakra Monsters" (チャクラのバケモノ, Chakura no Bakemono) The Land of Fire (火の国, Hi no Kuni) is famous for one of the largest and most powerful clans in the world, The Amano (なあ) clan. Homura (焔) Amano (なあ) the princess of that clan is the creator of the tailed beas...