This chapter was edited by PraetorXyn

Chapter 07 — The Man of the House

Dazzling rays of sunshine woke me from my slumber just when my dream got to the best part, as I became Hokage, with the whole village proclaiming my greatness. Even Sakura-chan was there, fawning over me with her pretty pink hair dancing in the wind. Without opening my eyes, I rolled over to the right side of my bed, away from the window.

I knew from experience this would buy me at least half an hour of sleep before the sunshine could reach me again, which was enough time for my dream to finish. I was about to burrow my head into the pillow again and for sleep to overtake me when I noticed the sun hadn't gone away.

Worse, it got even brighter. With a groan — still half asleep — I buried my head into my arms to shield them from the sun that shouldn't be there. It wasn't the only strange thing I noticed.

No matter how hard I racked my sleep-addled brain, I couldn't remember my pillow ever feeling this soft against my skin. It felt really nice. I wound up burrowing my face deeper into the pillow and slowly drifted back to sleep.

"Good morning, Naruto," I heard an angelic voice say.

That must have been my imagination playing a trick on me. Except nobody played tricks on the Prankster King of Konoha, Uzumaki Naruto — not even his own mind. I slowly opened my eyes and risked a peek from under my arm.

I blinked away the black spots from looking into the light. It was all coming in through a massive window that hadn't been there when I went to bed last night. Surely, I would remember such a huge window — or the white marble walls to the left and right of it.

Where did that wall and window come from? Tracing my fingers over the blanket confirmed its softness. It was so very unlike my scratchy old one.

Suddenly I was wide awake, and sleeping was a distant afterthought. I did my best to keep my racing heart under control. I sat up and came face to face with some lady. My body instantly froze up at seeing her.

The lady was sitting in an armchair next to the bed I'd woken up in. I couldn't help but stare at her. "Pretty" escaped my mouth before I could clamp it shut. She wasn't as pretty as Sakura-chan with her beautiful pink hair: nobody was. I'd bet Sakura-chan would be even prettier in a white kimono with red flowers like the one the lady was wearing. I nodded along while chastising myself for straying.

Jiji once told me a man shouldn't look at other women and admire them, because it's the first step to betraying them — and I'd never betray Sakura-chan — although, I didn't understand how thinking a girl was pretty would lead to betraying her. When I asked Jiji what he meant, he nearly choked on the nasty-smelling smoke of his pipe and said I would understand when I'm older. He says that a lot when I ask him something. Come to think of it now — it was odd that he wouldn't meet my eyes for some time after it happened. When he eventually answered, he got really serious — even using his Hokage voice — and told me some strange story about flowers and bees.

The soft chuckling at my antics from the Lady reminded me that I wasn't alone. "It seems, I was correct in choosing my attire."

"Who're you, and what are you doing in my…" I screeched to a halt in the middle of my outburst, only now realizing that this wasn't my room. It was huge — larger than my whole apartment, in fact. The things I could see in the room also looked so nice and expensive.

"Are you rich, lady?" was the next thing coming out of my mouth before I could stop myself. This really wasn't what I should be asking her after waking up somewhere unfamiliar. She thought so too, judging by the glee in her expression. It was different, somehow, though, lacking the dismissiveness and condescension I was used to from adults.

Glaring at her with crossed arms in front of my chest, I asked, "Where are we?"

Instead of answering, she only chuckled harder. With the heat rising to my cheeks, I continued. "I shall let you know that the great Uzumaki Naruto — future Hokage of Konoha — won't be intimidated by likes of you, you villain."

"A villain am I?" she questioned with a playfully offended glint in her eyes.

"Yeah, you know, with kidnapping me and all. Isn't that what villains do? Although… shouldn't you have kidnapped a princess so the hero could save her and live happily ever after?"

"Perhaps I should have. The problem with that is princesses are hard to come by these days." Leaning forward in her chair, she wondered, "But a beautiful girl might do just as well. Do you know of any I could use for my insidious plans?"

"Nope. I won't tell you anything about Sakura-chan — not even if you do bad things to me."

"Sakura-chan," she repeated in a saccharine manner while I blanched, realizing what I had let slip. "Who is that?"

Instead of answering, I used both hands to keep myself from telling anything else.

"You remind me a lot of your mother. She also had trouble keeping a secret, and she was just as easy to fluster and tease."

"yihip nögnögw," I pressed out, with my hands still clasped over my mouth.

"I didn't catch that. Can you repeat it?"

"I said I'm not falling for your tricks again," I told her, lifting the hands off my mouth. "You won't get another word out of me."

"But I just did," she said, smiling. I tried my hardest to glare at her in response and pressed down harder on the hands covering my mouth.

"That's such a shame. I was about to tell you about your mother. Since your self-imposed silence will prevent you from asking any questions — of which I'm sure you have many — it might be for the best to adjourn talking about her until you change your mind. Even us villains have limits to the evils we are willing to commit."

She knew things about my mother! I repeated her words in my mind. "No, wait!" I desperately shouted and then cautiously asked, "You really knew her? This is no trick? Because I won't forgive you if it is!"

"It is not a trick, Naruto. I really knew her and your father. In fact, I was their best friend."

"How?" I questioned. "Hokage-jiji said he doesn't know who my mother was, and that I'm just an orphan."

"Oh, did he now. That's very interesting." Somehow, her words made the hairs on the back of my neck stand up.

"Before we come back to this, I should probably start by introducing myself. My name is Uchiha Mikoto. You might know me as Sayuri's mother."

"Huh," I huffed. "I've seen her mom, and you aren't her!"

"Are you perhaps referring to a young woman with black hair worn in a ponytail?"

"Yeah," I nodded.

"That was Kasumi, our housekeeper."

"Housekeeper," I repeated after her. "You mean she lives here, too?"

"Why are you asking, Naruto?"

"She is mean and always glares at me," I huffed.

"Don't worry, she won't bother you again," she said. Her voice had a peculiar undertone that sent a cold shiver down my spine. "Since nobody saw fit to tell you the truth about your mother, let's start with the basics. Your mother — Kushina — was sent from her home — the island of Uzushio — to Konoha. She was to take the aging Uzumaki Mito's place in her function as Konoha's jinchūriki."

"There's another Uzumaki in the village?! How come I don't know her?! And what's a shushuriki-dattebayo?"

"Jinchūriki," the lady automatically corrected. After a long pause, she added, "They did not deem it necessary to tell you?"

"Tell me what?" I wondered.

"Apparently, the village did not just keep information about your mother from you." With a heavy sigh, she asked, "What do you know about the kyūbi attack?"

"Oh, I know. I know everything about it, dattebayo," I said, jittery. "It's about that evil nine-tailed fox that attacked the village, the one the Fourth Hokage killed, right? He is a hero. I think that makes him the best of all the Hokage, and when I'm all grown up, I'll be even stronger than him." I wasn't sure what it was, but something I said made the lady smile a bit, which made me smile back.

"That is not wrong, but it is not the whole truth either. Sometimes omitting something can be just as bad as lying."

"Huh?" I wondered aloud, "I don't get it."

"It might become clearer if I use an example, so bear please with me. Imagine one of your classmates insults your dream of becoming Hokage and doesn't stop even after you have asked him to. Instead, he only gets meaner, and he shoves you around to make his point, telling your other classmates that you are too weak to succeed." Wow, that's nearly exactly what happened a few weeks ago when that jerk Kiba made fun of me.

"Imagine that it eventually got to be too much. No longer able to contain your anger, you go after him. Unfortunately, you only get one hit in before your teacher comes into the classroom and separates you. The first thing the other kid does is snitch to the teacher that you attacked him. His words are not wrong, but they aren't the entire truth either, because he withheld everything that led up to that point — which prompted your attack in the first place — obscuring by omission what really happened. As a result, you are the only one who gets punished, because you aren't allowed to explain your side of the story."

Yeah, Iruka sensei wouldn't even want to listen to what I had to say — so unfair.

"It is essentially the same as what you know about the kyūbi attack. You only know half the story — less even. And superficial knowledge can be dangerous," she explained. "I wonder why the Hokage would do that?" she added as an afterthought.

Yeah, why would Jiji not tell me?

"Regardless," she said with renewed focus, "the word jinchūriki literally means 'power of human sacrifice.' When Uchiha Madara — one of the founders of Konoha — tried to destroy Konoha over a difference in opinion on how to run the village. The first Hokage and his wife Uzumaki Mito — the other two founders — met him in battle. Madara — aware of Hashirama being more than his equal in battle — didn't come alone. He brought the most powerful being he could get his hands on with him."

"The kyūbi," I mumbled.

"In that confrontation — which reshaped the entire landscape — it was Mito who ultimately defeated that beast by sealing it into herself, thereby becoming the first jinchūriki. Ultimately, it was Mito's sacrifice that allowed Hashirama to triumph over Madara."

"What's sealing?" I wondered.

The lady just looked at me unblinking, "They did not… of course they did not… why should they allow an Uzumaki to know about — let alone learn — fūinjutsu," she grouched. "Your mother used to say sealing — or fūinjutsu — is the art of bending the universe to your whim with paint and a brush. I'm sure you have seen a few shinobi use scrolls that they used to make items appear out of or disappear."

I nodded.

"Those were simple sealing scrolls — it is one of the most basic and widespread applications of fūinjutsu. And just like nin, tai, and genjutsu, only those pursuing to master it get an idea of what can be truly done with it. Both your father and mother were considered sealmasters. Not many of those remained after the fall of Uzushio, and the resulting near-extinction of the Uzumaki clan. It's an art — one I'm sure you will excel at, as it is in your blood. And before you know it, you will call yourself a master, too."

"Really? So they were great shinobi?" I asked, fearful of the answer.

"The greatest, Naruto. I mean, even you said so already."

"Huh."

With a chuckle, she said, "Mere moments ago, you said, and I quote, 'the Fourth was the greatest,' or did I mishear you?"

"No, I said that, but what…" I asked when it clicked. "The Fourth is my…"

"Yes, he is," she confirmed. "Your mother was his wife. I can assure you they loved you very much."

"How…?"

"How do I know?" she repeated. "Because I knew them better than anyone else. Perhaps it is better to show you to make you believe. Right next to you, on your nightstand, are some old pictures they made me draw of them."

Blinking, I turned my head. Just like she said, there were three picture frames facing sideways on the nightstand. Shuffling under the blanket, I moved closer and reached for the first frame within range.

"They did that all the time. I was out of the village on a mission — a really boring one — escorting some merchant and his wares. To alleviate that boredom, I ended up strolling through one of the villages we stopped at. It was there I came across an artist. He was sitting in the town square and painted portraits of the people for a fee. With nothing better to do and those eyes we have, I spent the afternoon watching him. So, when your mother literally dragged me to Teuchi for some ramen immediately upon my return to the village, she ended up rummaging through my backpack, looking for money, because she had forgotten to bring her wallet. What she found instead were my first paintings. From then on, it was always 'Mikoto-chan, can you paint me doing this or that?' The lengths she went to… one time she even tried to bribe me with…"

I tuned her out the instant I laid eyes on the picture. It showed a man resting his head on a red-headed woman's big stomach.

"Ah, I drew the one you are holding a week before your birth when you were still in your mother's belly. It is the only existing drawing with all three of you in it. I took it from her nightstand. She would have wanted you to have it."

"They look happy," I croaked out. Wondering what was wrong with my voice as teardrops landed on the glass covering the picture.

"Oh, that is a huge understatement if ever there was one. They weren't just happy. They were insufferably sweet to each other. Just being around them posed the risk of dying from sugar poisoning."

Trailing the woman's — my mother's — hair, I was mesmerized by how beautiful she was. Her hair was even prettier than Sakura-chan's. No wonder my father fell for her. He looked just like the face on the mountain, just in color. And then there was me…

"Compared to this, the other two drawings are nothing special: just two portraits of both your parents."

Finally able to tear my eyes away from the picture and back to the lady, I managed to gasp out, "Thank you, Thank you so much."

"Wait until I show you their rooms."

"Their rooms?!" I shouted, unable to contain my excitement, and I tried to get out of bed, only to get tangled up in the blanket.

"Slow down, Naruto. Their rooms aren't running away. We have plenty of time to visit them later. But first, let me finish telling you about them."

"You promise?" I asked while wiping away my tears.

She sounded sincere when she said, "I would never lie to you."

"They are dead," I mumbled.

"Yes, that is the one thing they did not lie to you about. They were killed the night you were born."

"By the kyūbi…"

"Not exactly. The fox was the tool used to kill your parents. And — like any other tool — someone wielded it. This is the reason why I told you about jinchūriki."

"Those people with monsters… sealed into them, right?"

"Yes," she agreed. "You see, when a jinchūriki nears the end of their life, something has to be done about their bijū, since they can't be killed. Either they would break free upon the death of their host, or reform a few years later. Both are not outcomes that would be in the village's best interest. In one case, the kyūbimight take exception to having been imprisoned for decades and take it out on the Konoha, and in the other case, it would rob the village of its weapon of war for at least the duration it takes the kyūbito reform. With your parents gone, the chances of recapturing the beast without the help of the First Hokage's Mokuton or a sealmistress of Mito Uzumaki caliber at hand would be slim to none. So the village's precious weapon could be lost for good or — what is considered worse — end up in the hands of our enemies."

"Weapon? You lost me, lady. I thought the jin-whatever was a woman and the kyūbi was a fox."

"Ah, sorry, I should have explained that better," she apologized. "You see, a jinchūriki doesn't just effectively work as a prison for the beast. They can also draw upon its power. This can make even a mediocre shinobi into one that can — at least for some time — go toe to toe with a village elite."

"Woah, so these schinschuriki…"

"Jinchūriki…" she interrupted.

"Are super strong?"

"You could say that, yes. Usually, the more experienced the jinchūriki, the more power they can draw upon. An example of this is Bee, the eight-tailed jinchūriki of Kumo. He is able to fully utilize the power of his bijū, making him one of the most formidable shinobi of our time. This shouldn't come as a surprise, as while the other bijū are generally considered weaker than the kyūbi,they are the lesser version of a creature that nearly single-handedly wiped out the whole village. Thus, every jinchūriki is considered a strategic military asset because they are potential army killers. And since every one of the five great villages is in possession of at least one of them, you can see why Konoha wouldn't want to lose theirs. Admittedly, Konoha has never had to rely on their jinchūriki to win their wars in the entirety of its history, but that might not always be the case."

"Hmm," I mulled over what I had heard. "So, how come the kyūbigot free, then? Did this Mito-lady die?"

"Mito did die, but that was years before the kyūbi attack."

"Huh, then how…" I was confused.

"There are other situations in which the seals holding bijū are at risk of collapsing. Generally speaking, whenever the jinchūriki is severely weakened the seals keeping the bijū at bay, weaken alongside them. After all, their seals are primarily sustained by the jinchūriki's chakra.

For a woman, this occurs whenever she gives birth to a child. Naruto, your mother Kushina was brought to Konoha for the explicit purpose of becoming Mito's successor as the jinchūriki of the kyūbi. In other words, she was the second jinchūriki of the nine-tailed demon fox, and you are its third."

"Huh?" What was she saying? That couldn't be true, right?!

"I understand that my word alone might not be enough to believe me. Open your kimono and mold some chakra, and then look at your belly." I did what she asked, and some strange scribblings appeared on my stomach.

"What you are seeing is the Hakke no Fūin Shiki, the seal your father used to seal the kyūbi inside of you."

"That means it was my fault that… so that's why nobody likes me…"

"It was not your fault. Never, and I mean NEVER let anyone tell you anything different. If it was anyone's fault, it was the man's who attacked your parents when the seal was at its weakest in an attempt to weaponize the kyūbi."

"Somebody attacked them?" I asked, aghast. "Why didn't anybody tell me?"

"There is no easy answer to that, so bear with me for a minute. The man who attacked your parents was named Obito, and he was a cousin of mine. Remember when I told you how Uchiha Madara used the kyūbi in his fight against the First Hokage? The reason he could do that was because of his special eyes that allowed him to control it."

I nodded along.

"Obito had the same eyes as Madara. He used them to rip the kyūbi from your mother's seal and pit it against the village. Meanwhile, your father was fighting him. By chance, I arrived just when your father won and went to battle against the kyūbi." Of course he did, the Fourth was the strongest. "But the kyūbi was not the only one acting at someone else's bidding. My cousin was not the only one with special eyes. My father, Kagami, also had special eyes, and he made me hide Obito's body."

"Why would he do that?"

The lady grimaced. "Were you ever falsely accused of something you didn't do?"

I nodded enthusiastically. "All the time. Just because I pranked a few classmates, they always say it's me who did something even though I didn't, honest."

"I believe you," she reassured. "It is sort of the same when it comes to my clan. Some people think that because Uchiha Madara attacked the village, everyone related to him is the same. So if the village would have found out that someone sharing our surname had tried to destroy the village using the kyūbi and was responsible for all the deaths, the rest of us — although innocent, like you were — would have been blamed."

"I see, I see," I nodded along. This lady was really good at explaining things. I wish the teachers in the academy would be just as good.

"Not that it stopped them," she bemoaned.

"Huh, but you hid that bad man's body."

"I did. However, there are only two people known to have had the ability to exert control over the bijū. Senju Hashirama and Uchiha Madara, and only the latter has people sharing those traits that allowed him to do that, while Hashirama's descendants lost that ability. Hence the Uchiha clan — as a whole — has been a prime suspect this entire time. The people who thought the rest of us had something to do with the attack didn't exactly make a secret out of it."

"People glared at you, too," I asked.

"They did," she said. "The difference being the members of my clan have always been proud and arrogant to a fault. A volatile combination of ingredients. Of course, they couldn't let those accusations stand."

"Neither would I," I told her. "So, you pranked them?"

Chuckling, she said, "Perhaps they should have tried that. It might have worked out better in the end. But no, that is not what they did. I won't bore you with the details, but all they did over the last few years made everything worse. Eventually, they were fed up and reached the conclusion that the only way out was to kill everyone involved in their treatment."

"Wait, are you telling me this because…"

"No," she denied before I could finish. "I didn't allow it to get that far."

"Puh," I exclaimed, "so Jiji and Ayame are…"

"They are okay and enjoying their good health. But I digress. We were talking about jinchūriki and the fact that you are following in Mito and your mother's footsteps keeping the monster at bay. You are the reason that the village and everybody within it is safe. You are a hero, and you deserve to be treated as such."

"You really think so lady?"

"Yes, I do," she insisted. "I promised to always be truthful with you, and I keep my promises."

"As do I," I declared. "It is important to keep your promises."

"It is," she agreed. "So, you can believe me when I say that even if every breath you take would not ultimately be responsible for the village's continued existence, who your parents were should have ensured an entirely different upbringing. The least they should have done was tell you about your parents and allow you to live in your own home."

"Home? I own a house?!"

"You are in it, and it is not just the house; the surrounding area is yours, too."

Boah, I immediately tried to scramble to my feet to take a look outside. Somehow the blanket I threw off was still there, and my feet got tangled up in it. Before I knew what was happening, I fell off the bed, and the ground was coming closer really fast. I barely had time to think, 'This is gonna hurt,' when I stopped in midair — inches away from faceplanting into the floor.

"Careful, you might hurt yourself," the lady warned as she carefully sat me down on the bed. She then awkwardly crouched down because her dress was getting in the way. Worriedly, she looked me over for injuries, I think. Just like I had watched moms do to their children when they fell on the playground.

"Don't worry, I'm tough," I nervously told her.

For some reason, she spontaneously hugged me. "Of course you are." After my surprise wore off, I melted into her embrace. It felt really nice, being held like that. "Nonetheless, as your godmother, it is my responsibility to protect you."

Wiggling out of her grasp, I wondered, "God-mother, what's that?"

Pulling back from the embrace, with one hand placed on my shoulder, she explained, "A godmother — or a god-father, respectively — is a woman or man your parents choose to trust with the care of their, in case something happens to them."

"Like death?"

"Yes, like death." I shrug off her loose touch. "You can think of it like a substitute mother and father."

"Then where were you all my life!? When people told me no one would ever love me, that no one would care if I died! Where were you through all of that?!" I shouted at her, holding back tears.

"I'm sorry, Naruto. I would have liked nothing more than to have been there for you from the moment your parents were ripped from this world and both of our lives, but there were people — bad people — who didn't allow me to."

What is that lady saying? I could have had a mother all this time, but didn't because of some jackasses? "Where are they now?" I asked with a hard edge to my voice. "Keeping you away from me deserves a thrashing from yours truly, Uzumaki Naruto."

Chuckling she said, "Indeed it does." She then softly caressed my cheek, "Rest assured, I have taken care of them. They will not bother anyone ever again."

A cold shiver ran down my spine at the glint in her eyes as she said those words, and only a meek 'okay' made it past my lips. Now, I understood why Shikamaru says moms are scary, because they absolutely are.

"So, you are my new okā-san?" She was taken aback by my question for an instant.

"Yes, if you want me to be—" I tackled her and didn't start sobbing uncontrollably in the crane of her neck. Shinobi don't cry, and I will become the greatest shinobi there ever was, like my mom and dad. "I will become everything you need me to be." I didn't pay attention to what she said after that.

I just held onto her for what felt like forever.

I couldn't really believe anything she said. It was too good to be true, all of my wishes coming true. I pinched my cheek, making sure that this wasn't a dream or some goun-jutsu the old man told me about — although he never did tell me how to get out of one. I just have to hope for it not to be one then.

Not that I wanted this to stop. To the contrary, I loved this… whatever this was… even if the lady sometimes gave me the creeps. Yet I couldn't live with waking up knowing that this was all just my imagination playing tricks on me. Having my deepest wish fulfilled — only for it to be taken away from me again — would crush me.

"There were so many precious moments I have missed: your first step, your first words… so many things irrevocably lost to us. I'll do my best to make up for every single one of them."

That was when my stomach grumbled. With a chuckle, my new mother freed herself from my embrace and put me down on the ground beside her. Standing up, she put out her hand. "Shall we take a look and see if we can find you something to eat? Your mother would come and haunt me if I allowed you to go hungry."

I took her outstretched hand, and she led me through the vast house.I could only stare in silent wonder at the tapestries and portraits the hallways were decorated with. It was while looking at a painting of some huge whirlpool in front of an Island that an otherwordly smell reached my nose and my mouth began to water. Following the scent of food, I heard the fussing sounds of a child before we stepped through a huge double door into a room full of people.

I froze on the spot, totally taken by surprise. The room stilled, and all the black-haired and beautiful girls turned to us as, and as one fell to their knees and chanted, "Welcome home, Naruto-sama. The Uchiha clan greets their lord." Even the toddlers held in the arms of the older girls joined in with them.

"Let me formally introduce myself again, Naruto-sama," the lady said as she released my hand from her grip and rounded on me until she came to a stop in front of me. "My name is Uchiha Mikoto, daughter of the deceased Uchiha Kagami. Named your godmother by my best friend — your late mother Uzumaki Kushina — and your late father, Namikaze Minato. My friends call me Miko, my enemies call me Raven and you may call me okā-san." She then fell to her knees. "I, as the clan leader of the Uchiha clan, hereby swear myself and my clan to you." Her next words were echoed by everybody present. "May your will become our will, your allies our allies, and your enemies our enemies. We swear to never act against you, whether by thought, action, or inaction. Let us be the sword that strikes at your enemies and the shield that guards your back. We pledge our lives, minds, and bodies to you. May our servitude last for all eternity."

Authors Note: The reason Yagura wasn't mentioned as a perfect jinchūriki is two-fold: given that we learn from Bee (a perfect jinchūriki is effectively immune to any form of genjutsu including Tsukuyomi whose effects take hold near instantly) I found it highly implausible for Obito or Madara to have managed to put them in one, not without it essentially being a contradiction. Of course, plain-out immunities are usually a bad concept, so in game terms, it's more like an incredibly high resistance, but the fact remains: if that was possible to do with an S-rank shinobi with perfect control over a bijū, why wasn't it possible with any of the other jinchūriki?

To solve this conundrum and to make sense of the situation, I always assumed that Yagura was in fact not a perfect jinchūriki. Instead, Madara and later Obito used Amenominakanushi or the unnamed and unexplained canon equivalent and put both Yagura and the three tails in two separate genjutsu, and then forced to work together, thereby creating a "perfect jinchūriki" in the first place.

It solves a few issues I have with the whole thing — although admittedly adding or more precisely expanding on the fact that Sharingan or Mangekyō Sharingan users can enter the inner world of a jinchūriki is something I also have strong reservations about.

Since I won't make use of that mechanic, either assume that Yagura drew on the three-tails' chakra and at least partially manifested Isobu for Madara or Obito to even have a chance to use a genjutsu on him.

Two, Yagura's age is not clearly established, and neither is when he came into power. So, chances are since he at this point should be Mizukage already, Mikoto is unaware of his skillset, having been retired for roughly a decade at this point.

Some of you might have noticed that the seal on Naruto's stomach is not the Eight Trigrams Seal used in canon. For one, I'm absolutely no friend of the kyūbi being separated into two entities, and even less of how that was handled in canon (aka Minato coming back from the dead with full control over his half without any training whatsoever, in addition to him also being a Sage. It made each of Naruto's accomplishments up to that point pale in comparison to his father's).

Additionally, the seals look awfully similar, and not many fanfic writers bother with the distinction between them (which I'm not entirely certain was originally planned to begin with, nor did the reason given make any real sense IMO — aka that the kyūbi was too strong to seal him in its entirety — so then why not use a Shinigami powered seal to do the job? I mean, the Shiki Fuin is supposed to seal stuff in the stomach of the Shinigami in order to take care of it for good — at least that is what we are led to believe. I mean, you summon the friggin god of death to rip something out of the land of the living… what else would we think it would do right? Only to later learn, yeah being inside the Shinigami's stomach isn't nearly as final as we were led to believe: you see it is in fact super easy to escape… SO WHAT WAS THE FRIGGING POINT? — especially since the stomach of the Shinigami is accessible from anywhere — in contrast to sealing something within a scroll… making the whole "get your hands on the object" entirely obsolete. Sure you need the Shinigami mask (an object that just came up this once to make that possible and never again), which we don't even know if there is more than one, if it can be replicated, etc).

So essentially, Naruto has a modified Shiki Fuin on his stomach that is powered by the Shinigami and his father's soul that sealed the entirety of the kyūbi inside of him (and not the Shinigami's stomach).