Shunned ((Naruto X OC))

Prologue

 Kyuubi's small feet patted on the ground. He panted heavily and ran for his target. A black fox a few feet ahead. "Kumaru! Wait up!" He panted.
"Come and get me if you can!" The black fox up ahead laughed. Kyuubi pushed himself harder and nearly caught up to his sister when she suddenly stopped. The two siblings collided.
Kumaru growled. "Hey! You idiot! That hurt!"
Kyuubi looked around. "Where are we?"
The two foxes found themselves in a dark forest. The black fox shrugged. "How should I know?"
"Do you think the others are here?" The brother wondered. Kumaru scoffed. "We don't need them! The more tails-"
"The stronger." Kyuubi finished their saying. Kumaru grinned and waved her many tails in her brother's face. "Good job." She smiled a toothy grin. Kyuubi sneezed and yawned. "Yea. Shukaku is a weakling and we don't need weaklings."
Kumaru nuzzled her brother's cheek and lay beside him.
'Your heart is as black as ever sister.'

-Many years later-
"Sister! Give it up!" The nine tails roared. Kumaru waved her long black tails and bared her teeth. "You're a weakling! This time! Time time I will win!"
Ropes tied the black fox down. She struggled under the grasp of the shinobi. "Fools!"
Across the village, her brother had been sealed away in a small child. "You can't control me! You can never!"
"Tie it down! Seal it away!" A ninja called.
"Idots!"
Kumaru felt a pull in her body and everything went black.
The demon fox opened her eyes. She was locked in a large cage. A seal on the bars. The room was dark and cold and all Kumaru could feel was hate, anger, regret. "You just wait Hokage of the Leaf.... You just wait." She cackled and stuck her claws though the bars. "You'll be sorry."