I don't InuYasha. I do own Castria and Serenity though

I am sorry about taking so long to update, but I was having a bit of a writer's block and then I watched InuYasha last night and it all came back to me. Enjoy! It may be a bit before I update again because I have two tests coming up that I HAVE to study for, so wish me luck.

It was quite a shock on the half-demon, but it was expected. Sesshomaru carefully picked up the fainted one from the floor and carried her back to her room. He then turned to Castria.

"When she awakens, have her bathed and brought to my study. She needs to be taught some respect."

Rin looked at her sister with wide eyes. What had she said to upset Lord Sesshomaru so much? The little girl didn't think much on it before bouncing out the door to the gardens and to torment Jaken some more.

Castria nodded at her lord before exiting the room behind the young girl.

Sesshomaru sighed and looked at this damn half-breed that he was forced to show compassion to thanks to her young sister, his ward, who had him wrapped around her small finger.

Sesshomaru left the room and headed off to another part his home. He couldn't remember the last time he just wandered the halls and was left to his thoughts.

Slowly making his way to his study on the other end of his massive castle, Sesshomaru thought about the last four years, and why Rin never mentioned having a sister in all that time, especially one that was a half-demon like his own brother.

Perhaps she thought her sister dead, or she had simply forgotten about her until she saw her again.

Several demon servants passed Sesshomaru and after bowing would continue on their ways. Sesshomaru's mind was so wrapped up in his thoughts that he barely even knew anyone was around him.

There was also the question of why Serenity didn't come to Rin's rescue when her family died, or when the wolves attacked her. Of course, it was doubtful that Serenity was given much time to get to know her sister, especially with the way Rin described the way that they treated her when she was around.

Reaching the door to his study Sesshomaru made a decision.

"Half-breeds are worthless beings that will never be accepted by humans or demons. They shouldn't even exist, the pathetic, weak creatures," he said to himself before entering his study and moving his mind to his work.

Serenity awoke several hours later in complete shock of the whole affair. Castria was waiting for her by her bed with a kimono and bathing items.

"My lord wishes to speak with you when you are finished bathing and are dressed."

Serenity didn't speak, just nodded and followed Castria to the hot spring where she quickly bathed and dressed.

Castria was surprised at this girl's sudden change. One minute she was ready to fight and the next she was quiet and docile. It was quite strange.

"Are you alright?" Castria asked finally. Serenity turned to her and smiled.

"Yeah, just in shock that my sister has been staying here with Lord Sesshomaru…even though she is human. With the way he treated me, one would think that he didn't care for humans at all, or even those who had a little human in them."

"The young Miss' relationship with my lord is quite unique itself. It is unusual to see them apart for too long."

Serenity nodded before they stopped in front a set of large doors. "This is his study?"

Castria nodded before leaving Serenity at the doors. "Good luck," she said leaving the half-demon at the door.

Serenity calmed her breathing and beating heart before knocking on the door.

Sesshomaru was reading, which is something he did when he wanted to relax, when he heard someone knock on his door. "Enter," he said closing his book and standing. The door opened and Serenity walked in.

Now without the stench of blood and dirt on her, Sesshomaru could make out a sweet scent of lavender and roses. The girl herself had changed from the bloody, disgusting mess that had insulted him earlier, to a beautiful vision in a simple blue kimono.

Her silver hair was now washed and tied back with a simple ribbon. Her green eyes sparkled in the dim light coming in from the window from the setting sun. Even the ears on her head didn't stop Sesshomaru from thinking that this girl was the most beautiful woman he had ever seen.

"You wanted to see me, my lord?"

Sesshomaru was knocked back to reality at her words. Luckily he had learned to school his features to always appear neutral, so she remained unaware of what had been distracting his thoughts for the last few moments.

Serenity was feeling quite strange standing there in front of this very attractive dog demon and he seems to be lost in his own thoughts.

"Yes," he said finally. "I wanted to discuss your remaining here. After that little stunt you pulled earlier, you are lucky to be alive. However, because you are Rin's sister, I am forced to show you some sort of respect, and if you wish to remain here you will do the same."

Serenity could feel the anger swelling up inside her again. Respect? That was what he demanded?

"Very well, but I ask that you no longer call me a 'half-breed' or 'half-demon.' I am quite aware that is what I am, so I ask that you don't remind me further. I have a name and I want you to use it. In exchange I will show you the proper respect, my lord."

Sesshomaru nodded. "Very well. You are dismissed."

Serenity didn't need to be told twice. She turned and left the room, with no more words to Sesshomaru, to find Rin. Sesshomaru returned to his book, this time with a strange feeling that this was going to come back and bite him in the ass.

Serenity stayed in Sesshomaru's home for almost a month, avoiding him very well. The only time she ever saw him was at meals and the occasional time she passed him in the hallway.

Serenity awoke one morning to find that her body was suddenly hypersensitive. She sighed in understanding, she was in heat. It happened every month when the full moon came round, and would last for five to six days.

When Castria came in like normal, she instantly knew something was up. "Serenity?"

Serenity looked over at Castria and nodded. "I'm here. Would you please tell my lord that I cannot attend any meals today with him and Rin? I am afraid that my presence at the current time would not be a welcome thing."

"Why is that?"

Serenity groaned. Her body was going crazy and she was losing some control. Unlike most half-demons, who lose their demonic powers at certain times, she losses control of hers when she goes into heat. It was the reason she had remained locked away during those times after it first happened. Once she realized she was about to kill a human, she decided to have herself locked away each month to protect her from other demons, and the humans from her.

"Please don't ask questions and just do as I ask."

Castria nodded and left the room quickly. That girl looked like she had red in her eyes. Is her inner demon trying to get out?

Castria quickly walked to the dining room, where Lord Sesshomaru, Rin, and Jaken were already seated waiting on Serenity.

"I am sorry sir," Castria said bowing, "but Miss Serenity has fallen ill and has said she will be unable to attend meals for several nights. She also requests that she be left alone during this time."

Sesshomaru narrowed his eyes slightly at this, but decided it must be important and at least she respected him enough to let him know.

"Very well," he said. "Please prepare a breakfast plate for her and take it to her."

Little Rin was worried. Her sister was sick and her lord was just sitting there doing nothing about it.

"My Lord," Rin said suddenly. "Please see to my sister. I know that she is a half-demon and I worry for her. What if something is terribly wrong with her?"

Sesshomaru sighed inwardly. This child was his one weakness, and anything she asked for her would be willing to give.

"I promise to check up on her if she does not attend supper tonight."

Rin smiled brightly before going back to her breakfast. Jaken didn't care one way or the other. One less half-demon in the world wouldn't bother him.

Supper passed and there was still no sign of Serenity. Several servants had walked by her quarters and heard loud growls, panting, and several things being either ripped, torn, or thrown in that room. Castria was the only one brave enough to go in there, but even she didn't remain long.

As it was, Sesshomaru had a promise to keep and headed to Serenity's quarters after supper. It was surprisingly quiet despite all the talk that had been going around.

Sesshomaru was about to open the door, when Castria walked out and accidentally bumped into him.

"I'm so sorry my lord," she said. "Was there something you required of me?"

"No…actually yes. Tell me, you have been the only one to see Serenity all day. Tell me what ails her."

Castria shook her head. "I know not my lord. One would think that she was in heat, but the way she is acting suggests otherwise. When demons going into heat, they seek out males, usually the one they are mated too, but she willingly remains locked away in her room, causing violent outbursts and behavior."

Sesshomaru nodded at this. Yes, it was quite strange that Serenity would be acting like this.

"I promised Rin I would check up on her personally," Sesshomaru said reaching for the door.

"Good luck my lord," Castria said before hurrying down the hallway.

Sesshomaru opened the door and entered the dark room.