Chapter One: My Second Life with System-sama!
The moonlight in Tokyo had a particular charm, especially when it poured through the glass facade of a luxurious apartment overlooking the city lights that never sleep. But for Tsukio, the moon was nothing more than a signal telling him, "The shift is finally over."
He tossed his keys onto the marble table. His body screamed from exhaustion. As a doctor, the word "emergency" was the true alarm of his life. Today, he had spent six hours in the operating room battling to save a patient from severe internal bleeding. He was the leader, the person in charge of the operation, and now he was just a human in need of his bed.
He entered the bathroom and let the warm water wash away the tension in his muscles and the smell of antiseptics that clung to his skin like a shadow. He stepped out, wrapping a towel around his waist, heading toward the kitchen.
"Midnight… eat or sleep?" he murmured to himself as he opened the fridge.
Logic said, "Sleep," but his stomach had more authority in that moment. He prepared a quick dish of nibachi soba with a boiled egg. Tomorrow was a day off, and this was the only luxury he had: not setting an alarm.
After dinner, Tsukio jumped onto his bed with a childlike enthusiasm unbefitting his esteemed position as a doctor. He pulled a stack of paper volumes from the side shelf, still smelling of fresh ink.
"One Piece."
This was the addiction no medicine had ever cured. Due to work pressure, ten full volumes had piled up. He bought them regularly since he had the money, and now it was time.
He sighed as he opened the first volume: "Why did I start this journey in the first place? Luffy, little one… when will you become the Pirate King and let me live my life in peace?"
He began to read. At first, he analyzed the scenes with a doctor's logic:
"How did Zoro not die from this wound? This tear needs at least 50 stitches and immediate blood transfusion!"
(For context, I haven't actually watched One Piece 🫠)
Then, gradually, he was drawn into the story. He laughed softly at the Straw Hat crew's antics, and felt pressure in his chest during the tense moments.
"Damn, Oda (the author) is a genius… but sadistic. How can a story be this long? I feel I'll retire before they reach Raftel Island."
An hour passed, then two. His eyes began to narrow. The letters danced before his eyes. He tried to fight off sleep to finish the current volume, but the surgery he performed that morning started taking its toll.
The volume slipped from his hands onto his chest.
"Just… one more page…" he murmured, voice thick with sleep.
Moonlight crept across his pale face as the "Chief Doctor" surrendered to deep sleep amidst piles of manga, dreaming of ships sailing in distant seas, far from operating rooms and the noise of Tokyo.
…
A full month passed… one month was enough to slap his "medical" logic against the wall.
I was reborn. Yes, the phrase I had read in silly web novels during my free time had become my reality. At first, I thought it was a dream caused by reading manga before sleep, but the texture of the blankets, the smell of wood, and the sound of my uncontrollable infantile crying confirmed the bitter truth: Tsukio had become a baby wearing diapers.
This is embarrassing!
The most important question: Where am I?
Based on what I saw and heard (and with the help of System-sama), I realized I was in the world of "Demon Slayer" (Kimetsu no Yaiba).
And then I paused a bit… why? Why am I not in One Piece? I spent my last night reading about Luffy! I was supposed to wake up wearing a straw hat, not wake up in a world where demons eat humans like midnight snacks.
Am I destined never to see the end of One Piece even in my second life?!
But how did a one-month-old baby know all this? The answer was: System-sama.
It wasn't a "super" system giving gifts from nothing; it was like an advanced AI attached to my consciousness. System told me it had been modifying my genes since I was a fetus. And the result?
My appearance was very strange for Japan in this era. Snow-white skin, pure white hair streaked with red strands falling on my forehead, and crimson red eyes. As for my body… System described it in words I couldn't tell whether were praise or insult:
"Congratulations, host. Your current vitality surpasses that of cockroaches."
Thanks, System. That really boosts my confidence.
The problem wasn't my hair color, but the "mark" extending from my neck to my chest, and another on my forehead. It was a Demon Slayer mark, and I also inherently possessed the Transparent World.
As for my father, Kenji, he initially looked at me with terror as if I were a harbinger of doom or a cursed child, just like the legend Yoruichi. Without my mother Hana's firm yet gentle discipline (I felt pain just looking at her), he would have thrown me into the river in the first week. Thanks to Hana-san, my father gradually accepted that I was just a "special" child, not a demon.
I try not to get too attached to them. We are in the world of Demon Slayer, and the first rule here is: "Your family is always in danger." If I became emotionally attached and then lost them, I couldn't bear it as a doctor whose purpose was to save lives. Yet, who am I fooling? My heart flutters every time Hana hugs me.
System told me I was born the same year as the story's hero, Tanjiro Kamado.
"This is the perfect time to build your strength," System said in its cold voice.
Honestly, without this System, I wouldn't have considered touching a sword. I'm a doctor; I fear monsters that eat humans alive! But System assured me that my talent rivaled that of Tsugikuni Yoruichi himself.
It made sense, since I possessed the Transparent World and the mark from birth, and System-sama was there to help me train.
Since I had this power and full knowledge of future events, I made my decision. I would not stand by. I remember clearly crying while reading the final chapters of the manga, those sacrifices, the death of beloved characters, and the sad endings.
I would change that future. Muzan and the demons… I will be your worst nightmare.
But now, being a baby… System-sama, can you stop comparing me to cockroaches and focus on the training plan?
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I've regained my passion. You can help me keep it by writing a comment if you want…
This novel won't be chaotic like "Dimension Traveler," and I'll do my best to make it enjoyable for you. Thank you…
Question: Do you want us to follow the original story closely, or deviate a bit?