Heir to the Blue by 18piker

Words: 13k+

Link: https://m.fanfiction.net/s/14292288/1/

What if Shirou was an Aozaki?

Chapter 1

(Before you read this I recommend you read Mahoyo first, You'll have a better understanding of the characters here once you do.)

Prologue

1987- Misaki countryside

Aoko Aozaki held the doorknob to her old family home. It was just one hour away from the start of a new year. She took a deep breath as she began to turn it. The warmth of her old home brought back some old memories, both good and bad, that made it hard for her to not smile at it all.

"I'm home!" she called out.

Her parents' eyes glowed in excitement at the sight of seeing their youngest daughter return for the first time in two years.

"Welcome home Aoko!" they both said to her warmly.

Her father stood up as he walked over to hug her. He was rather tall for his fellow countrymen, standing at over 180 cm with a burly build he built up from tending to the family farm. His red hair graying out on the sides of his head but his beard kept the old red hair he used to have all over his head in his younger days.

Her mother had black hair with azure colored eyes. One could say that she was a splitting image of Aoko, or that Aoko was a splitting image of her mother.

She wore a simple blue dress with a shawl over her shoulders to keep her warm. Some freckles and wrinkles showed up on both of them from all of the sun they got from working outside tending to the crops and animals they took care of.

He turned around to his wife and said, "Emi go get our guest, Aoko needs to see this."

"Oh of course Haru! I was just waiting for you to give me the word!"

Aoko's mother was almost jumping with excitement. She wondered what on earth did her parents have in store for her.

But

That warm feeling she had began to turn cold when she saw a familiar set of shoes walk downstairs with her mother.

"Impossible! HOW DID SHE—?"

It was Touko walking down with her mother, but what really stopped Aoko's thoughts was what her sister was carrying in her arms. Periodically gently shaking what she carried up and down as she slowly descended.

"Hello again Aoko." Touko said smugly.

"Say hello to your nephew, his name is Shirou, Shirou Aozaki."

Aoko was at a loss of words. Her sister, who she cursed not a few days ago was back here. Question after question ran through her head.

'When did she get pregnant? Why did she hide this from us?! Is this why she went through the trouble of nearly killing me!?'

Aoko wanted to be angry at Touko but all her anger was quickly stopped in its tracks when her father placed his hand on her shoulder again.

"We wanted to tell you sooner but Touko cast a spell on your mother and I that prevented us from calling you about the news. But honestly I can now see why. Your reaction is just priceless!"

He laughed as he finished.

Emi chuckled for a bit too.

"Oh dear there's no need to tease Aoko about this. She's just as shocked as we were when Touko arrived at our door two months ago."

"TWO MONTHS!?" Aoko cried out in shock and frustration.

Her cries woke up the infant in Touko's arms. He cried out for protection from whatever woke him up. Touko rocked him gently in her arms once more and hummed a lullaby to calm her son down.

It eventually worked. But then Touko gave her sister a scolding stare through her glasses.

"You should be more careful with that voice of yours around him."

Aoko wanted to scream more. Her blood boiled.

"You went through the trouble of making a kid that can inherit the 5th just to prove yourself better than me?!" Aoko was almost shaking in anger.

"Oh no, honestly I barely remember the night he was conceived. Learned the hard way to stay away from Jell-O Shots." Touko almost looked embarrassed as she said that.

Aoko felt another headache coming in.

"Now now girls," their father said, "there's no need to get into another fight. As hard as it is for you two, can we just keep tonight quiet."

"I am in agreement there dad." Touko said as she adjusted her glasses. "I need to discuss a deal with Aoko anyway."

Their mother shook her head in disappointment, but at least this was an improvement over how they last talked to each other in this house.

"Hm. Fine then." Aoko said with a hint of anger and annoyance in her voice. "What do you want to discuss then?"

"Let's discuss this somewhere a bit more private." Touko moved towards the dining room, as she sat down she undid her button up shirt to start nursing her son, moving her free hand to remove her glasses, her voice deepening and becoming more serious as she did. Aoko followed her, ready to ask her sister several questions.

"I'm surprised you managed to keep your son's existence a secret for so long." Aoko Started.

"Does it? Aoko I have a sealing designation, Lugh is but my first line of defense for my little Shirou." Touko explained briefly.

"Anyway," Aoko changed back to the original topic, trying to push back the memories of that golden wolf biting her neck. "How did you figure out which body was your real one?"

"When I started having strange cravings and got regular morning sickness. That's when I decided to test myself. After it came back positive I decided to take a risk and…" Touko stopped herself as she removed her son from her breast and handed over Shirou to Aoko so she could fix her shirt.

"Careful with him."

"Of course. He is pretty cute!" Aoko's heart melted at the moment she held onto her nephew.

"Back to what I was saying." Touko continued "To make sure that this body was indeed my original body, I took a knife to my left hand and." She stopped as she held up the palm of her left hand. Aoko saw what her sister did to herself. It was a nasty, ugly scar from a knife.

"You carved your own hand to make sure that you weren't a puppet. Clever." Aoko almost wanted to vomit over complimenting her sister. She tried to forget it by just rocking her nephew in her arms. The last question in her head came back as she looked at his sleepy face.

"Is he the reason why you tried to kill me?" Aoko finally asked her sister as she looked up to face her once more. An aura of bloodlust came off of her.

Touko paused for a moment as she pulled out some nicotine gum to deal with her urge to smoke. She sighed after taking a deep breath and took a second to collect her thoughts. There wasn't going to be a good answer for her sister.

"Partly." Touko answered honestly. Aoko's eyes told Touko how strong her sister's rage was.

"I was just furious over what you took from me. But now it's starting to mean less and less to me. Right now, all I want is to make sure my son is safe, and eventually train him. Without getting grandfather involved." Touko's voice was filled with venom as she mentioned their grandfather. The old man mostly responsible for the deadly fights happening between the Aozaki sisters.

Aoko paused for a moment, she was indeed furious but also understood her sister's stance on the topic. She thought about it for a second as she looked back down to Shirou before giving him back to his mother.

"Can't say I blame you on that last part." Aoko sighed as her anger gradually left her. "Honestly, I agree we need to keep him away from that old man. But what's stopping you from harming my friends again? Or stealing my stuff?!"

Touko almost laughed as she put her glasses back on, her voice becoming more cheerful as she finished.

"Why sister, this." She pulled out a yellowed paper from her back pocket and passed it over to Aoko across the table.

Aoko was shocked when she realized it was a Geis Scroll. She had to look back at it and her sister to make sure she wasn't dreaming. This should be the absolute last thing her sister would ever make.

That stopped when she read the terms of conditions on the scroll. It was too good, so good in fact that Aoko began to smirk at her sister. Too many good ideas passing through with this deal it was too good to pass up.

"Sure." Aoko said after reading and signing the scroll. "I'll help you raise and train him."

Author's note- Hello everyone. Long time no see. Sorry for not updating my previous stories but sadly I abandoned them and now focusing on this because I am back in college and trying to get that done. So the only thing I will have time to write for fun is this.

This isn't going to be another OP shirou power fantasy fanfic because there are plenty of those. Shirou will only get 1 additional ability until he gets to the clock tower. That's it, that is all he's getting. I'll leave it up to you to figure it out.