It was a normal day at the Emiya Household. At least, it was as normal as it could be. A boisterous girl came crashing into the shed near the compound. She ran into the shed before jumping up in the air and landing on top of the sleeping boy.

"Shirou, it's time to get up!" She broadly smiled, happy she woke him up before Sakura this time.

The boy opened his eyes, locking his sight on the white-haired girl. He smiled, patting the girl's head.

"Good morning, Illya."

"Yeah, yeah, good morning Shirou. Come on, Taiga is being annoying again you need to calm her down!" Shirou let out a little laugh. In the short time Illya and Fuji-nee had been acquainted, they were almost always bickering. Illya took note of his little laugh, pouting that he wasn't taking her seriously.

"It's not funny, this is serious!"

"Yes, yes, I know. All she needs is breakfast. As they both entered the household, they were met with their usual guests. An annoyed Taiga and Sakura, who was consoling her. As Taiga looked up, her brows furrowed focusing all her anger on Shirou's face.

"Shirouu, where's the food? I have been waiting for hours, I'm starving!"

"It hasn't been hours, stop exaggerating." Shirou headed into the kitchen ready to prepare breakfast for everyone. Sakura followed as the two of them prepared food as they usually did. Despite the noisiness, Shirou appreciated these mornings. He looked back at Illya and Fuji-nee, who were in the middle of some squabble and smiled. Illya's presence made the house feel even more lively.

Still, there was one thing he thought of regarding the silver-haired girl. That being her past. He didn't know much about Illya's life before the war. She never gave much details about her family. The only thing he knew was her last name. Did she perhaps have an older brother in her past? Was that why she was completely fixated on him? Like he reminded her of someone she used to know? He wondered if he could ask her these questions. That is if she decided to open up about it. He never minded the attention Illya gave him. It comforted him and gave him warmth knowing Illya thought of him as her older brother. As the months went on, Illya did feel like his younger sister.

After breakfast, Fuji-nee and Illya would leave. They would go back to Fuji-nee's place and then come back for dinner later. Considering today was a holiday, Shirou didn't have any school. He wanted to take the time and bond with Illya. He knew the young girl would happily reciprocate spending time with him.

"Uh, Fuji-nee? Do you mind if Illya stays here with me? Since there's no school today, I thought Illya would like it if we hung out."

Before she could answer, Illya enthusiastically nodded her head. She grabbed Shirou's arm, a playful smile on her face. The older woman smiled, she knew Illya's soft spot for Shirou. Despite her arguments with the mischievous girl, Taiga adored her too. She knew Illya would like spending time with him, and she wasn't going to stop her.

"Alright, you two behave." She then got on her scooter and left. Shortly after Sakura left too, having other obligations to fulfill. That only left the two of them in the living room.

Should I bring up the question now? He pondered on it but decided not to. He can try bringing it up later, he didn't want to ruin Illya's mood first thing in the morning. As he was in thought, Illya waved her hand around his face.

"Shirouu, are you listening? I want to go to the shopping district, then we can go to the mall, then we can go to the park, and then-

"Slow down, I'm listening. Come on let's get going."

The two of them spent hours together doing everything Illya asked. Illya was nothing but happy. She twirled around, singing, and taking in everything she was seeing. She never once got tired, always ready to do the next thing. As they came back to the Emiya household, Shirou decided he would try asking her about her past.

"Illya, did you have fun?"

"Of course I did. I would be an idiot if I didn't have fun. She then bowed down.

"Thank you, Shirou, for spending time with me."

"Hey, you don't have to be so formal. It's just what families do." Shirou didn't realize he said that until it was already out.

"Eh, I'm Shirou's family?"

He didn't feel the need to correct himself. Why correct something that isn't wrong?

"Well, yeah. We have known each other for months now. You are someone I care a lot about, Illya." What followed was a sad smile from the girl.

"It's nice to be part of a family again. I didn't have one for years after-" She stopped herself, not wanting to bombard Shirou with her past.

"After what?"

"It's nothing Shirou, don't worry about it." That certainly wasn't nothing, Shirou wanted to know about her past even more now. He went up to Illya and hugged the small girl.

"Illya, you can tell me. I won't judge you or anything." She let go of the hug, looking down at the floor.

"I wish you did."

"What?"

"I wish you did judge me!" She raised her voice, louder than Shirou had ever heard before. Before she repeated the same words in a quieter tone. Looking at the boy, she began her barrage of self-hatred.

"After everything, I did to you. I wanted to kill you, and I almost did! I almost forced you to be my doll, and then unleashed Berserker on you in the forest! I'm a terrible person, Shirou! Yet you never showed anger towards me or hatred!"

"Illya, it's ok I don't hold a grudge against you. You changed, you aren't like that anymore."

"It's not ok! Why do you have to be like this? So...so...loving."

"Ilya, I'm not saying you didn't do bad things. But, you did change. You are someone I have grown to care a lot about. I forgive you, and you don't have to keep beating yourself over it. The war has been over for months now." She didn't say anything, still looking down on the floor.

"Shirou, you mean it right? We are family. You won't ever leave me?"

"Yeah, I'll never turn my back on you."

"I want to believe you. It's just...my last one didn't work out well."

"Illya if you don't want to share-"

"It's fine Shirou. I don't want to hide anything from you anymore. We are family, and you put a lot of trust in me. I should reciprocate and do the same." She took Shirou's arm, and both of them sat down in the living room.

"You know I'm an Einzbern already, and you saw where I lived. You also met my maids, Sella and Liz.

"Those were the 2 tall girls in your castle right?" She nodded her head, confirming Shirou's answer.

"My mothers name was Irisviel Von Einzbern. She died during the last Grail War. She took a deep breath, she was trying to speak but she couldn't. Every time she opened her mouth, no words would come out.

"My...my...my." She took another deep breath again.

"My father was Kiritsugu Emiya." The two of them sat there in silence. Shirou's eyes widened. Kiritsugu was also Illya's father? They really were related? Surely Kiritsugu would have told him about her right? He did try to think back on that time. Kiritsugu would go on business trips frequently. Was that where he was going? Was he trying to get Illya to live with them? Knowing what he did about the Einzberns, they were a powerful force. Kiritsugus's health was also rapidly declining, which meant he was always unsuccessful in bringing her back.

But then something nagged at his consciousness. The dark thought crawled into his brain and took control of all his senses. He didn't want to confront it, or give it power, but it was overwhelming.

He stole Kiritsugu from Illya. He deprived a young girl of her father. He was at fault for the girl's pain and loneliness.

"I'm sorry, Illya."

"W-what?"

"I'm sorry for taking him from you. I'm sorry for keeping him here when he should have been with you, I'm sorry-" A finger met his lips, stopping him instantly.

"No Shirou. It's not your fault. It was never your fault." Illya was deathly serious, her voice having no traces of the mischievousness or playfulness she usually had. She slowly brought her finger back, her arms slowly made their way around her knees.

"I just wish he tried to come back for me. I wish he didn't leave me all alone."

"He did try. Growing up, He would go on long trips periodically. He told me they were business trips, and I never thought twice about it. But now I can tell, Kiritisugu wouldn't leave you alone, he had to have tried.

Did Papa try to rescue her? Not just once, but multiple times? Tears didn't fall from her eyes, but they did build up. A small smile appeared on her mouth, as she reached for the boy.

"Thank you, Shirou. Thank you for telling me." She hugged him with all her might. The boy returned the hug, letting the girl know he cared and wouldn't leave her. The brother and sister embraced each other, not a word uttered for a long while. That was until Illya let out another deep breath.

"I don't know how long I'll live, but I'm happy I met you." This caused Shirou to look down at her. He was alarmed at what Illya told him.

"What does that mean?" She looked up at him, ready to explain something else about her. She didn't want to hide anything from him anymore. Even if she had to tell him about her shortened lifespan.

"Shirou, my body isn't meant to live long. I was meant to only function as the grail. Due to all the modifications done to my body, it severely cut my lifespan."

"But..there has to be a way right?" Shirou didn't want to hear this. He had someone he cared about, his last link to Kiritsugu. He couldn't lose her so soon, he had to save her!"

"I wish, Shirou. But, I don't think there is."

"There has to be!"

"SHIROU!" Shirou was at a loss for words. Illya had never yelled at him before. He wanted to refute, but he couldn't deny her words. All he could ask was a question he wished he didn't have to. Looking at her eyes, he knew she didn't want to yell. She didn't want this fate, but that's what life gave her.

"How...how long do you have?"

"I'm not sure, but the time will come sooner rather than later." There was nothing he could truly do here. He didn't know how to save her, nor comprehend ways to do it. All he could do was silently resign himself, and accept the facts. He hated himself, he couldn't even save his sister. How could he be a hero of justice if he can't save the one he loves? But even so, he would do everything to give her the happiness she was robbed of before the war. That was the least he could do.

"Illya, even if it isn't very long, I'll make sure your days are filled with happiness. I'll make sure you don't have to suffer anymore."

"You already have, Shirou. I want to live whatever time I have left here with you, Taiga, and everyone else. Please don't tell Taiga or anyone else, I don't want them to worry too."

"They will have to know someday."

"Maybe I'll tell them someday, but for now I want this between us." All Shirou could do was nod his head.

They continued to lay in their embrace, basking in each other's comfort. Illya soon spoke again, not quite done with her revelations.

"Oh, there's one more thing."

"Please don't be something bad."

"Oh, it's not anything bad." Her mischievous smile had come back. It caused Shirou to gulp, he didn't know what she was about to say.

"I'm the older sister! I'm a year older than you!" Illya laughed and then laughed even harder when she saw Shirou's shocked and bewildered face. She got up from their embrace, waltzing into the kitchen.

"Come on baby brother! You have to get started on dinner! Don't disappoint me!"

Despite his sadness and fear, now knowing Illya didn't have much time left. All Shirou could do was smile at her antics. He wasn't lying he would stick with her until the end. He would always support her and make her happy. He knew one day he would have to confront the sad fact, but for now, he wanted to think of the happy moments he could still have with her. His older sister was a handful. But he wouldn't want it any other way.