Onohara Meimei is one of the few remaining ninja members of the Onohara Clan. The Onohara were almost completely wiped out by the dominant Clan of the Land of Snow, known simply as the Snow-Nin. The Onohara were powerful, but relatively peaceful, and unprepared for a conflict with other ninja. Though they fought valiantly, the assault that had been intended merely to take control of the Onohara Clan wound up becoming a war of genocide. Almost all shinobi of the Onohara were killed, and many of the civilians were as well. Though the civilians have been taken in by the Snow-Nin, and successive generations have been taught it was the Uchiha who nearly eradicated the Onohara, there are still some shinobi of the Onohara who survived. They live on, and they remember the real enemy.
Meimei was born a few decades after the Clan Wars began and thus did not fully experience the murderous war waged against her people by the Snow-Nin. But she was aware from the moment she could understand spoken language, and comprehend the concept of "others", that her life, and the life of her family, was not normal. She was not allowed to be a little girl or to play or be innocent. Before she even knew who she was supposed to be fighting, she knew how to fight. She was only five when she started serious training. By the age of 7 she was the equivalent of a Student ready to graduate, and considerably more experienced in battle. Still, Meimei didn't understand the full importance of the hardships she suffered. She didn't understand why she had to hate the Snow-Nin. She didn't understand why they never stayed in one place for too long. Why they were always on the move, in the frigid and harsh Land of Snow.
She was not treated unfairly. Her family and her handful of other teachers cared about her. But they also made it clear that they weren't going to take it easy on her just because of that. They wanted her to grow and become strong, and the most assured way of doing that was to train her in all the skills that these few survivors of the genocide had picked up in their battles against the Snow-Nin. It was up to Meimei and perhaps a dozen others throughout the Land of Snow to take back what was stolen from them. It was up to them to destroy Yukigakure and the Snow-Nin. It was up to them to show the enthralled civilians of the Onohara the TRUTH about what had been done by the enemy.
Meimei was Genin-equivalent by the age of 9, and was on her way to become stronger. She occasionally met other children around her age. They were typically as cold and hard as she was, but there was always that desire in their eyes to be something else. Any time Meimei started to make friends, the camp would pull up stakes and depart, and Meimei would not see those friends again for years, if ever again. She hated having to be on the move all the time. She wanted to settle down and live in a house and not have to deal with any more training or fighting or anything else. The raids on Snow-Nin outposts and towns and such might have been necessary for survival, but that didn't make them any less unpleasant or any less stressful. She had already had to kill more than once. She didn't relish the idea of doing it for the rest of her life in the name of revenge. She just didn't understand.
Years passed, and Meimei grew physically, mentally, and in terms of overall power. Still, she had not managed to unlock the Kekkei Genkai of the Onohara… 'Shoumei'. Her parents had been Guardian Ninja within the Onohara, so it was expected she would be able to master the Shoumei as they had. Her failure in this regard nagged at her constantly. On her 16th birthday, during a meager meal that was supposed to be a celebration of Meimei's coming of age, the Snow-Nin found them. They had camped just a little bit too long in one place, and the Snow-Nin came down upon the Onohara with all the fury of a snowstorm. The Snow-Nin felt guilty for nearly wiping out the Onohara Clan to begin with. But they also had blamed the Uchiha for their crimes, and had outlawed the training of Onohara in combat or ninja skills of ANY KIND. This meant that survivors of the war were officially "traitors" to Yukigakure, and further, if these "traitors" revealed the truth about what had happened, they would be facing mass insurrection. Thus the Onohara ninja had to die.
Meimei never found out how many survived by fleeing into the wilderness. She just knew that the number of people she knew and trusted, the individuals who had been with her for her entire life, had been sharply reduced either through death, or through scattering to the four winds. She only survived by fleeing, rather than trying to fight against the attackers. Before she hadn't understood why she was being trained to fight. She hadn't understood the meaning of revenge. Now her family was dead or lost, and the rest… She didn't even know where the rest were, or if she'd ever see them again. She didn't understand before.
She understood now.
Meimei had no more teachers, so she had to teach herself. She had no one to push her anymore, so she pushed herself. She had no one to direct her towards the enemy, so she found her own direction. She had to become stronger. Only by becoming stronger, and by fulfilling the wishes of her family could she finally fulfill her purpose. She had to take back what was stolen. She had to destroy her enemies. And she had to reveal the truth to her people at last.
and Shoumei: Radiation Release 
