Peak Between Two: Mushoku Tensei

-Kazuya Hiroaki-

Pain.

Excruciating pain.

I had been shot once during an armed robbery incident back in college. I had also gone three days without sleep while completing a high-pressure research project. Hell, I had even nearly passed out from suffocation during a martial arts training session with Ryusei.

But compared to all of that... this was far worse.

It felt as if my entire body had been shattered into tiny fragments, then reassembled in the wrong way. As if I were being swallowed by something immense and suffocating, only to be mercilessly squeezed.

Damn it, what kind of nightmare is this?

Darkness. I couldn't see anything.

I felt cramped.

And why did my body feel like… it was being squeezed?!

"MMPH!!"

I tried to move, but I couldn't. My arms… my legs… they wouldn't respond!

Shit, am I still alive? I can't be trapped under wreckage from the crash, can I? No… this is different. I don't feel the pain of broken bones or bleeding wounds.

But what's even stranger… why do I feel like I'm writhing?!

Am I… shrinking?

As I started to panic, I suddenly heard something. A muffled sound. Like the rushing of water, but faintly mixed with voices.

I tried to focus.

"Stay strong, dear. Just a little more, you can do it!"

Wait.

Wait a second.

That was a woman's voice.

And she was speaking in a soft, loving tone.

I tried to listen more carefully, but the voice sounded too close—like it was coming from all around me.

"Huff… I can see the head! Just a little more!"

Hold on.

HEAD?!

A chill ran down my spine. I tried to move my arms and legs again, but it only made the space around me feel even tighter.

Oh no.

OH NO.

"One last push! Come on, just one more!"

I had no idea how to explain it, but I suddenly felt my body being pushed out.

And within seconds…

I saw light.

SHIT. DON'T TELL ME—

"UWAAAAAAAHHHH!!"

I… was crying?!

I WAS JUST BORN AGAIN?!

-Ryusei Takeda-

Cold air hit my body the moment I regained consciousness. I had no idea where I was, but one thing was clear… I was breathing.

No. I was forced to breathe.

My lungs felt foreign, my body didn't feel like my own, and the sound of crying babies echoed all around me.

Shit, this is really happening!

I wanted to scream, to demand an explanation for what was going on, but the only sound that came out of my mouth was—

"WAAAAAHHHH!!!"

...Dear God.

I had really been reborn as a baby.

"Congratulations, it's a boy!"

A woman smiled down at me, her face exhausted but filled with joy.

"My son… he's so handsome…"

Damn it.

I was really stuck in a baby's body.

And to make matters worse… I still had no idea what world I was in.

###

-Kazuya Hiroaki-

Three years had passed since the day I was reborn.

I still vividly remember how I, Kazuya Hiroaki, a genius scientist and renowned researcher, died in a car accident alongside my best friend, Ryusei.

I remember the sound of the pouring rain, the sensation of the car losing control, and… the deafening explosion before everything faded into darkness.

But what I don't understand is… why am I still here?

I was supposed to be dead.

And yet, I woke up… as a baby.

Reborn as a Greyrat

My new name is Luciel Greyrat.

Yes. Greyrat.

I don't know how or why, but I was reincarnated as the second son of Paul and Zenith Greyrat, a minor noble family living in a remote village called Buena Village.

I have an older brother named Rudeus, just a few years older than me.

I don't know who they are. I don't know what kind of world I've been reborn into. But one thing is clear—this is not the world I once knew.

From the moment I became aware of my surroundings, I noticed many strange things.

First, my body felt stronger and more energetic than an average baby's. I could crawl and lift my head faster than normal infants, and within just a few months, I was walking without assistance.

Second, the laws of physics in this world felt… off. I saw my mother and brother doing things that should have been impossible—they could create water from thin air.

It didn't take me long to realize that magic exists in this world.

And the most shocking part?

I could use it too.

Exploring a New World

Once I discovered that magic was real, I immediately began experimenting.

As a scientist, I refuse to accept anything without a clear understanding. If magic exists, then there must be rules and scientific principles governing its use.

I started observing every detail:

✔ How is magic used?

✔ How does it interact with the environment?

✔ Are there any limitations?

After years of conducting secret experiments, I began to grasp the fundamentals of magic in this world.

Mana is an energy that can be manipulated through willpower. It functions similarly to an electromagnetic field, but with greater flexibility. Magic can be cast with or without incantations. Incantations serve as a "mental aid" for those who haven't mastered direct mana control. Mana isn't just passive energy—it can be modified and optimized, just like technology!

I experimented alone at night, using my small hands to create water droplets, ignite small flames, and shift the ground beneath me.

The result?

By the time I turned three, I could already use Intermediate-Level Magic without incantations.

Of course, I kept this a secret from my family.

I didn't want to attract attention too soon.

I still don't fully understand how this world works, and I have no intention of becoming a test subject or being forced into something beyond my control.

For now, I'll play it safe.

But… one thing keeps bothering me.

Where is Ryusei?

I refuse to believe I'm the only one who experienced this.

Ryusei… my best friend… did he also reincarnate?

If he did, where is he now?

Was he reborn in the same family as me? Or did he end up in an entirely different place?

Or worse… did he not survive?

I don't know.

But one thing is certain—I will find him.

Because no matter what world we're in…

We are the ultimate duo.

And I know that fate will bring us together again.

-Ryusei Takeda-

"Hey! Stop running, you little brat!"

I chuckled as I dashed effortlessly through the trees. Behind me, an old man in a green robe chased after me, his face red with frustration. In his hands, he held a broom, ready to smack me at any moment.

"Hahaha! You're too slow, old man!"

I leaped onto a wooden fence, flipping midair before landing smoothly. The old man stumbled and nearly fell face-first into the ground.

"Damn it! Stop causing trouble, Ryusei!"

Yeah. My name used to be Ryusei Takeda.

Now, I'm known as Ryu Dedoldia, a child of the Beast Race living in the Great Forest.

The first time I realized I was no longer human, I was shocked. My ears were longer and sharper, my body more agile, and my sense of smell was unbelievably sharp. When I finally saw my reflection in a stream, I understood:

I had been reincarnated as a beastman from the Dedoldia Tribe.

I don't know who my parents were in this life, as I had been raised in the Dedoldia village's orphanage since infancy.

But honestly? I didn't care.

I was an ex-special forces soldier who had now been given a young and powerful body, enhanced with the superior physical abilities of the Beast Race. Compared to regular humans, I was faster, stronger, and more agile.

And I made the most of it.

For the past three years, I had trained my body nonstop. Martial arts, reflexes, endurance—I pushed my limits every single day. I refused to be weak in this world.

And the result?

Even as a child, I could already defeat adults in combat.

But there was one thing that frustrated me…

I couldn't use magic.

Unlike humans like Kazuya, beastmen weren't naturally gifted with mana. I had tried countless times, but my mana reserves were far smaller than a regular human's.

But that didn't matter. I didn't need magic.

I had strength and instincts far sharper than any spellcaster.

Three years in this world had taught me one thing—I have to keep growing stronger.

I don't know if I'll ever see Kazuya again, but I know he's alive somewhere in this world.

Until then… I'll keep training.

And when we finally reunite—

We'll show this world why we were the best team back on Earth.