A pecking order had been established. Inutashio beat up on Sesshomaru, not because he hated his elder son, but because he loved him and wanted to toughen him up for the rigors of life that lay ahead of him, not realizing that his son's silent nature was not because of softness, but because of a coldness that meant he was more than adequate prepare for the life that lay ahead of his ascension to the throne.
But from there it snowballed. Sesshomaru in turn beat up on Inuyasha, feeling the need to retaliate for his father's punishments. He justified his actions in that Inuyasha was a worthless half demon, not deserving of his status in life, and so something needed to be done to order the score. Inuyasha resented his brother because of this, but because most of the rest of the city's population treated him like trash also, he had accepted that he was trash, and so he didn't try to retaliate.
But, he needed to do something to alleviate the tension and frustration he felt. So, he had found a human girl to beat on. That girl, named Kikyo, loved Inuyasha with all of her heart, and looked past the beatings to the man that really lay inside of Inuyasha. Inuyasha justified his beating of her in that she needed some sense beaten into her because there was no way that she should be bothered to pursue her affections of him. He was worthless.
Kikyo was bothered by Inuyasha's beating of her, but she loved him too much to force the issue. Rather, she beat on the orphans of the castle, trying to toughen them up for the rigors of what lay ahead in the eventual servant’s position they would probably eventually find themselves in, for if Inuyasha beat her, then he would probably beat the servants when he ascended to the position of Lord.
The orphans, named Shippou, Rin, Kohaku, Kirara, Shiori, and Kanna formed a protective bond amongst each other, and would never strike another one of them except in playfulness. But, there was one taking care of them, feeding them, playing with them, watching over them, protecting them from everyone except Kikyo that they felt the need to beat on. Their fists and feet couldn't do much damage, but they did hurt their protector, and she just accepted it, knowing that the children were being abused, as most every member of the castle was. She just hoped that one day, her accepting of the punishment and refusing to continue the chain, pouring out love instead of injury would lead to change. Her stopping of the chain meant that it was confined to the castle and didn't spread to the city or the Kingdom in general.
Her name, the Orphan Keeper, was Kagome Higurashi. Like Kikyo, she wore makeup over her bruises, the ones that could be concealed. When the children would come at her, they would come at her in a mob, the girls biting, clawing, and kicking her, the boys punching and biting as well. The demon children left fang and claw marks, and the humans and half demons light scratch marks, and all of them left bruises. They didn't have the strength to break bones, but on a fair number of occasions, she had been left light headed by concussions and blood loss.
A pecking order had been established, but like all things created, it had to come to an end. She was sure someone would kill one of their tormenters, but she was wrong. The one who would do the killing, whom would end the order, was not one being abused, nor one doing the abusing. Rather, it was one who watched from the sidelines, who was enjoying the entire spectacle for his own amusement. The chaos that would soon follow, he would enjoy immensely.