It had been a few days since Stella's abrupt death and rebirth. In that time, she had realized a few things.

First, she seemed to be a danger magnet in her new life. She didn't know exactly what happened after she was born, but she definitely remembered a bunch of scary roars. And she also remembered her big brother's serious face. Something that shouldn't be on a kid like that.

And speaking of her big brother... The second thing Stella had realized was that she had a super capable older brother, despite him only being like ten years old at max.

Stella was well aware that she was just a newborn. And while she didn't know what happened, it must have been something pretty crazy. Even so, her big brother put on a brave face and tried his best to keep her calm and safe.

The third thing she realized was a result of her big brother's attempts to keep her calm and safe. And that was...

"Honestly, Stella. What did your Onii-chan do, huh?"

...Her big brother was a cheat reincarnator from Japan.

White hair, glowing green eyes... and the ability to casually use magic that even surprised the scary people around him. Scary people who looked like they belonged to a Demon Lord's army... and the tiny girl that looked like a Demon Lord as well.

Onii-chan picked Stella up and then sighed. "All I wanted to do was to play with you and your big sisters back at home now that we got through all of Dad's shenanigans, but *no.* That stupid Being W keeps messing with our lives. And I think he's still doing it now. Seriously. Is he trying passive aggressive now that direct aggression isn't working?"

"Gah?" Stella babbled a bit and then tilted her head, playing the part of a cute little baby.

It was embarrassing. Super embarrassing.

But it made her Onii-chan smile and relax.

Like now.

"Heh." Onii-chan reached out to tickle Stella's cheek and said, "At least someone's finding this funny."

Stella tried to keep a straight face, but her stupid baby body naturally reacted and started giggling.

Onii-chan smiled and then said, "You really are cute, aren't you, Stella?" After that, his smile faded and he said, "Mom and Mama Lily would have spoiled you silly. And Norn would have been so proud to say she was a big sister. Aisha too." He paused and said, "Dad probably would do some embarrassing things though, so probably better he's not around. Don't want him setting a bad example and you catching his stupid like I did."

Stella giggled.

From that description and those names, it seemed like Stella had reincarnated to a noble's family. And from how cute her Onii-chan was, she didn't doubt that was the case.

Maybe that was her repayment for dying early and saving Akito's life? She didn't have to, but a good turn seemed to be returned by another. Maybe this was karma?

"*Master Rudeus. The new recruits have adjusted to their bodies.*"

A charming male voice speaking a foreign language. With it came a knight in fancy silver armor.

Stella didn't understand the language, but it seemed like a baby's learning capacity was paying off since she didn't need to. The words came into her ears and she just naturally understood them, like magic.

Also, she forgot. Onii-chan's name was Rudeus, but he went by Rudy. A sign that he was still a kid despite his maturity.

Maybe he was being affected by his body too, like how Stella was acting like a baby?

Onii-chan... *Rudy* looked at Stella and sighed. "Onii-chan will be right back, Stella. Be good, okay?"

The face of a person bogged down by stress and mental fatigue. Like those salarymen always sleeping on the trains.

Seeing that, Stella let out a bright smile and babbled to cheer him up.

Rudy smiled back and then set Stella down in her crib. After that, she heard him walking away while talking in that foreign language.

"*Thanks, Roland. I'll take it from here. Could you watch Stella? Just to keep her safe.*"

"*Understood.*"

Rudy's footsteps faded into the distance. At the same time, the sound of clanking metal approached and that silver knight appeared in Stella's field of view.

An intimidating presence. Although the person seemed like a heroic knight, there was something about the man that gave Stella a bad feeling. The crimson eyes seemed to be judging her, as if staring at a puzzle that shouldn't exist.

So Stella decided to ignore him. Yep. Leave the scary stuff to her cheat reincarnator Onii-chan.

For now though...

'What should I do?'

That was the question she had to figure out.

Stella was dead. She accepted that fact. Dwelling on it wouldn't do any good.

...She missed home a bit. Her parents would be sad, and Akito definitely would be traumatized.

Served him right though for getting upset at her just for making a new guy friend.

...Hah.

Stella stared at the ceiling and sighed.

She was just a floppy and fragile baby right now. If she could, she would love to stand up and help her new Onii-chan with his fun experiments. Especially since he seemed to be a really smart guy.

Seriously. Casually mentioning stuff like using a Laplace Transform to integrate differential equations modeling various mana flows into a simple equation... Was he a professor in his past life? No, he sang a bunch of Anime songs as lullabies for her, so maybe he was just a super Otaku? But he didn't give off that creepy Otaku vibe...

"*Rolo!*" A somewhat grating and arrogant female's voice.

Stella winced and tried to look over. But her stupid baby body still didn't want to listen to her.

Fortunately... or unfortunately, the speaker quickly came into view and peered at Stella through the bars of the crib.

"*Why did Rudy tell you to watch Stella? Rika is much more capable!*"

The knight finally looked away from Stella and then said, "*I am here to defend the baby, not babysit. There is a difference. But you are free to do the latter.*"

"*Oh. Really? I-I mean... Of course! Rudy knows that Rika would be the best babysitter! Bwahahaha!*"

...Okay. Another thing to add to the list of things Stella learned. It seemed like she might have been reincarnated as the baby sister of a Demon Lord...

-SNG-

Time passed and settled into a typical daily routine. Or maybe 'atypical' was a better word to describe it?

Since Stella was just a newborn infant, she couldn't do much of anything on her own. She could think, watch, and listen. But in terms of moving around, taking care of herself... It was all dependent on Rudy nii-chan.

Which was embarrassing since she couldn't use the bathroom by herself and had to sit there and watch as her Onii-chan changed her diapers. Also as he fed her and burped her.

Still, she thought it was better than having to breastfeed. The embarrassment of that...

But anyway, Stella had gotten used to her new life, as weird as it might be. And as she did, she realized just how weird her Onii-chan was.

First of all, he was scary smart.

In her previous life, Stella had been top of her class. She also took advanced mathematics and all the high level courses she could take.

But Rudy nii-chan was on a different level entirely, casually muttering things about black holes distorting spacetime fields and potentially causing multiversal collapses. Also muttering entire sequences of mathematical equations outloud while staring at complex geometric designs and graphs.

Yes. Stella was sure that her Onii-chan was a professor of some sort before being reincarnated. Especially since he seemed to have the tolerance of a saint when dealing with the ridiculous cast of characters around him.

But anyway, her daily routine.

For the most part, Stella actually wasn't in her crib. Maybe since she got into the habit of smiling and giggling to cheer Rudy nii-chan up, he started carrying her around more.

...Or maybe it was so he wouldn't beat up the people giving him headaches. There had been more than a few times she saw her Onii-chan's eye twitch while he forcibly took some deep breaths to calm down.

Whatever the case, Rudy carried Stella around most of the day, setting her down only to change her.

Normally, Stella would have been annoyed. It was embarrassing. Demeaning.

Except that meant she got to see all of the ridiculously interesting things that her Onii-chan was up to.

Like designing an elaborate blueprint for a floating fortress or disassembling an automaton made out of steel and magical circuits to perform maintenance.

She also got to meet her Onii-chan's friends. Or maybe 'minions' were better?

The first was a scary guy with green hair and a red gem in the middle of his forehead. Ruijerd.

Stella remembered him. That man was someone who put her Onii-chan on edge and also radiated 'bad guy' energy. Enough that she kept crying even though she hadn't been really scared.

Stupid baby body and instincts.

But anyway, her incredible Onii-chan had managed to recruit that guy as an ally and even get rid of that scary vibe. And for the most part, he seemed like a nice Oji-san. At least, he always gave Stella a calm smile when he visited.

...Though he also always visited while being covered in blood, so maybe he was still a bit scary.

Second was a chuuni girl called Rika. Well, she seemed to actually be a demon of some kind from her horns, but for the most part she just acted like a delusional middle school girl playing at a Demon Lord. Especially since Rudy had to coax her a lot before she decided to stop wearing a skimpy outfit and start wearing more conservative black dresses that Rudy made.

Still, while a bit weird, Rika was nice. She had a lot of interesting stories and things to say on the rare occasions where Rudy had to let someone else watch Stella.

Rika was also the first to volunteer for those babysitting sessions and spent a lot of time telling Stella to not let her big brother devolve into a genocidal God Emperor who went around conquering and assimilating the most powerful demons to combat the Human God in a heaven-shaking battle.

...Stella had a feeling that Rika might have gotten too much into her roleplay.

As for Rudy's last friend/minion, it was the scary knight guy. On the surface, he seemed like a perfect knight. He even had the name of a famous one on Earth: Roland. Plus, he acted diligently and listened to every order Rudy gave.

But Stella noticed that he also seemed weird. Like... Almost like staring into an abyss.

Especially when Roland looked at her.

The knight seemed to always be looking at her like someone staring at a fascinating science exhibit. The sort of gaze that a person had at a zoo, watching the animals.

Weird. Weird, and a bit scary.

But he didn't do anything else.

...Still didn't mean that Stella didn't reach out for the first person she could get whenever that man was around though.

Anyway, that was her life now.

Stella was carried around by her Onii-chan while he went about his daily life of acting like a benevolent demon lord who ordered his minions to subjugate monsters, save people in need, and spread the name of Demon Lord 'Rudras' who owed a favor to Rudeus Notos Greyrat and was searching for his friends and family.

In short... A kingdom building simulator. While making a homebase, her Onii-chan was gathering resources and forces to look for their family who... appeared to have gotten lost in some big incident?

Stella wasn't sure, but there was one thing she *was* sure of.

'Onii-chan is incredible.'

Yes. Her Onii-chan was incredible.

That, and she couldn't wait until she could move her flimsy baby body around and talk so that she could join in on the magic experiments.

And find out just who her Onii-chan was in his past life. Because he *had* to be some kind of super genius or leader of a massive shadowy administration.

Right?

HappyVainGlory

The more I thought about it, the more I realized that a lot of Nanahoshi's character revolved around her trying to get back home and having no intention to interact with this one because she had a life waiting back for her on Earth.

That's not true here since Truck-san got her and got her good. Because of that... and because of the situations around her birth, I think she'll be quite a bit different and grow into her own character as 'Stella' instead of Nanahoshi/Shizuka.

Though I will say that this has interesting ripple effects down the line considering the overarching canon of Mushoku Tensei. More on that later though.

Next chapter, Rudy settles into his life as the Master of Chald- The Doctor of Rhodes Isl- The CEO of Coff-

...The protagonist of a gacha game who gets thrown into a position he's underqualified for and manages to make work through the power of plot armor, determination, and relying on the much more competent subordinates appearing through walking right into the gates of gacha hell.

P.S. Cookie for figuring out what S.N.G stands for. There are two interpretations I'm thinking of, but cookies for any other that fit.