Disclaimer: I don't own Inuyasha or Naruto.
Ever since he was a kid, Shippo knew he was different. He was left on the doorstep of an old human couple. Having no kids they decided to raise him as their own. Despite his dietary needs of straight meat, his slower aging, and his fiery blue eyes he was treated relatively well for a while. Then the other kids started reaching adolescence and he was left way behind physically. Needless to say, he was picked on and beat up a lot by the bigger kids.
Then one day he saw a girl in the village that he had never seen before. Her name was Shirori and he fell in love with her the moment he saw her. It took him two weeks to work up the courage to even talk to her. When he finally did, a group of boys intercepted him on his way.
The leader of the thugs, a boy named Hiruu said, "What are you thinking? She is way too good for your kind, you little demon! Looks like we'll have to teach you a lesson once and for all. Get him!" With that they jumped him and began to beat him. They just kept kicking him while he was on the ground and there was no one around to stop them this time. He was going to die here, on the ground, like some kind of rodent.
"NO!" something inside him yelled, "They are the rodents! They are the ones who deserve to die!" With that he felt a great flame rise up inside him, fueled by his hatred, anger and fear. He had a feeling of pleasant warmth and felt unbelievably calm. The thugs backed away as the grass around him withered and died from the heat and little orbs of flame appeared. The boys turned to run away, but Shippo locked his gaze on Hiruu, all of his hatred and anger flowing into him like an electrical current until he was filled with the fire and burst into violent blue flames. Shippo's gaze rested on each of the boys, setting little fires on their bodies.
As suddenly as the flame came, it was gone, along with all the hate and anger it used. Shippo came to and, realizing what he had done, collapsed into a sitting position. There were people all around, horrified at the demonic spectacle before them. He was brought on trial and banished (mainly because they didn't have the guts to try and kill him). He wandered around for two years. In those two years he grew, taller and bigger, until he was about six feet tall and 190 pounds with hardly any fat on him. He also learned to summon and control the flame to an extent. In order to survive in the wilderness, he learned to live in the shadows. He lived alone for four years, perfectly content, having pushed the village from his mind. Until one day…