Hello and welcome to this crossover fic! The Inuyasha verse is not with the story line, it's past it. The Naruto verse is in line. With some soon-to-be obvious variations of course. Enjoy!
"Sir! There has been an incident!"
"What is it Kakashi?"
"Another break-in and attack against Naruto Sir, but…"
"But?"
"Well, Risa's back. It seems she protected him. She's not letting anyone inside the apartment except you." Sarutobi nodded once and stood.
"Lead on."
They made it to the apartment quickly and Sarutobi barely spared a glance at the ANBU picking up the unconscious would-be attackers. He went up to the door and knocked, not even flinching at the energy that swept over him before the door unlocked and he strode inside. Risa was sitting on a chair, slowly rocking the blond infant.
"What is going on?"
"I am sure you all ready know. Naruto was attacked and I stopped them." Sarutobi pulled up the other chair and sat across from her.
"I realize that part. Why did you protect him, and why did you block off the apartment?"
"Because I'm taking him."
"What?!"
"… I made a promise to Minato nearly a year ago. I promised to protect his child if anything happened to him or Kushina. They're dead, and now Naruto was almost killed by his own village no less. As such I am going to take him instead."
"I can't-"
"I wasn't asking Sir. However; I would much rather make it… legal. So he could come back and learn to be a ninja once he's older." Sarutobi sighed and watched the sleeping boy for a moment.
"All right, but I need to know where you're taking him. Kakashi!" Sarutobi called out and Risa immediately let her shield barrier down so he could come in.
"Yes Sir?" Kakashi looked at Risa and Naruto questionably. "Is everything all right?"
"Yes. Go to my office and bring me Naruto's papers and an adoption sheet. Quickly."
"A-adoption Sir?"
"Yes. Now go." Kakashi disappeared, returning a minute later, handing the papers over.
"What's going on Sir?" Sarutobi ignored him and looked over the adoption paper, quickly filling most of it in.
"All right Risa, before I have you sign this you need to tell me where you're going to be."
"Of course. I presume you know of the barrier?" Risa glanced up at Kakashi.
"Vaguely. Explain it for us both."
"Both?"
"He's going to be a witness. If you don't mind Kakashi?"
"O-of course not Sir."
"Good. Feel free to sit down somewhere. So, the barrier?" Risa readjusted Naruto so she could lean back.
"The barrier separates your world from the demon world. It is located in the middle of a sea that you won't find on any maps. Most maps here tend to ignore the demon side all together for some odd reason, which makes it so very few people know it even exists. A poor way of managing affairs I think. Anyway, the sea itself is not just made of water and I wouldn't recommend trying to cross it. There is a ferry for it, but the ferryman rarely allows anyone across."
"What else is the sea made of?" Kakashi interrupted.
"Souls. It's the sea of souls: the Moien-nak. The demon side doesn't have ninja like it does here and, of course, there are many more demons about. The barrier actually prevents demon from crossing. It's mainly for those that can levitate, or fly, or something like that because the sea itself prevents travel otherwise. It'll even overturn any boats other than the ferryman's. I will be taking Naruto back with me to the demon side."
"Back with you?"
"Well, yeah. I lived on the demon side for many years before I came here."
"And when would he be brought back?"
"Well, whenever he should start school. Thinking about it now, I hope to only bring him here for small periods of time for learning. Not to live forever until he is an adult. And by adult I mean at the very least 16."
"How small are these periods?"
"I suppose it would be up to you. Although, seeing as how I'm not always welcome here and finding a place to stay for those periods would be difficult, I do hope it'll be less than a month at most." It was quiet for a while as Sarutobi thought it over before making a few notes on the adoption paper and sliding it over to her.
"When he is 7 you will start bringing him back here for one to two weeks at a time for schooling. We can figure out living arrangements then. And I want you to try and keep in touch during this time. As a member of this village you still should be going on missions." Risa looked over the paper and signed it, handing it over to Kakashi.
"Agreed. I know just how we could stay in touch too." She pulled off her necklace and set it on the table. "Move your hands off please." Sarutobi hastily removed his hands from the table as Risa closed her eyes and muttered a few unknown words, a hand hovering over the necklace. The entire table glowed brightly and when it dulled there were two necklaces. "There we go. Anytime you want to talk to me, a drop of blood on the gem will do it. You'll even be able to see a projection of me, and Naruto too if he's right next to me."
"And you can contact me as well?" Sarutobi took the paper back from Kakashi as Risa's head tilted.
"I believe so. Is there anything else?"
"Yes. You're going to stay here tonight. Meet me in my office tomorrow at noon. Good night, and congratulations on becoming a mother." He stood and walked away before she could object, but stopped Kakashi at the door, muttering something to him before leaving. Kakashi stood there for a moment before shutting the door and turning back to her.
"I've been ordered to stay here and assist you if need be."
"I'm sure he means well." She smiled at him and Kakashi half smiled as he sat down.
"Are you sure about this? Can you even take care of a kid?"
"I don't see why not. Besides, if I get too over my head there are people over there I can ask for help."
"Good, because based on his parents, this kid just might be a handful." Risa laughed.
"Luckily I have two hands."
The next morning Risa woke to Naruto crying again. She rolled off the bed and picked him up, bouncing him up and down as she rummaged around the small kitchen for a clue of what to give him. Kakashi tapped her on the shoulder and handed her a bottle, all ready warmed up. She grabbed it and waved it slowly in front of Naruto's face until he stopped crying and latched on.
"Thanks. Where'd you get that?"
"It was in the fridge. I had a feeling you'd be needing it soon."
"Hmm… You'd make a good parent. Want to come with me?" She laughed at his shocked face. "I'm kidding; taking him over is going to be enough of a hassle."
"If it's such a hassle why are you doing it?"
"I promised Minato I'd care for his kid if anything happened to them. And I can't stay here very easily."
"You have a home there?"
"Well, sort of. I don't have a house or anything if that's what you're asking."
"How are you going to protect him without a house?"
"By reputation and not leaving him alone."
"Reputation?"
"Demons aren't as complicated or insane as everyone seems to think." She paused to smile lightly down at Naruto. "Minato didn't judge me like that, it's one of the reasons I liked him so much."
"That doesn't tell me anything." Risa smirked at him.
"I know." She pulled the empty bottle away from the kid and dropped it into the sink. "What was that filled with?"
"Huh? A formula that replaces breast milk."
"… He can't eat food yet, can he?"
"I don't know. You'll have to ask the Hokage that. Speaking of which, we should get going."
Okay! Let me know if you need any clarification and I'll do my best to help you.