While awaiting the unfolding of events, the still unnamed baby wondered whether he would be burnt by the sun or not.

Opting for the serum, he imagined that, just like Tangiro in the story's conclusion, he would become immune to the sun, after all, the sun wouldn't harm its own child, right?

Since arriving in this world, he had been trying to remember as much as possible from the original work, but apart from a few fragments here and there, he barely remembered anything. His current biggest concern was the side effects of the serum.

Although the onis served as a reference for his situation, the truth was that he was unique. He didn't transform into an oni, but was born as one. And to complicate matters further, he must have the same blessing that the supposed ancestor of the sun should possess.

There are so many unknowns that almost give him a headache. Onis have pseudo-immortality, with super regeneration and great longevity, but all of this came from Muzan. He doesn't know if he will have the same abilities or weaknesses.

"Come to think of it, choosing the serum was more of a gamble than a certainty. I just hope my current body can grow. I don't even want to think about how to survive in a baby's body forever!" he pondered in a moment of reflection.

As the baby delved into his thoughts, his grandmother raced against time to organize things for the journey.

"If they want to kill my son... they'll have to go through... me first!" shouted the mother, holding the baby in her arms, tears in her eyes.

"Darling, I know it's hard... but you have to understand that we have no choice!" said the father, with a certain feeling of guilt, yet determined.

"Get out of here, coward who prefers to hand over your own child to death rather than fight for him!" exclaimed the woman, in a moment of fury.

Realizing that he couldn't calm the woman, the man left the house and went to an unknown location to reflect on his choices.

The grandmother listened to everything as she finished preparing for the escape. She knew the woman wouldn't let the baby be taken. Although it hurt to do so, she would help the woman escape with the baby, even knowing it was dangerous.

"Natsumi, come here, there's something I need to tell you," said the old lady, somberly.

The woman, weak from childbirth and extremely tired from the fights, still respected the lady who had helped her so much, so she went to her.

"I know it's hard for you to understand why they want to commit this atrocity, but you and the baby can't stay here. I've prepared these clothes and food for you. Go to the village of Yomoguita, you'll be safer there," explained the old woman as she handed over the supplies.

"Ma'am, I..."

"You don't need to say anything else, just take and go while it's still not dark. You need to find a place to shelter before nightfall. I've put a flint in the backpack, so you don't need to worry about making fire," said the grandmother, with a pained expression.

Taking the things prepared by the old lady, the woman wrapped her son to her chest and ran towards the mountains, towards the nearest village.

At nightfall, a group of villagers along with the old lady's son returned to the Tanaka family's house, only to find the old lady alone.

"Ayumi, where's the baby?" asked the old man, his voice filled with restrained anger.

"Far away from here, I hope!" replied the old lady, with a certain regret.

"Mother... where's Natsumi? You couldn't have done this, could you? Tell me you didn't, mother!" said the old lady's son, disbelieving and shocked.

"I did what was necessary and I don't regret it!" spoke the old lady, looking at the dark and cloudy sky, thinking of the mother and child, praying that they were safe.

On a snowy mountain, a trail of footprints stretched into the distance. Ahead of this path, a woman, bundled up in thick layers of clothing, walked determinedly forward. She murmured something as white clouds of vapor escaped her mouth due to the cold.

"Don't worry, my son... mommy will take care of everything. Your father may have abandoned you, but... I won't!" she asserted.

Watching that scene, the baby felt his stomach churn with guilt. If it weren't for him, the woman who was his mother in this life wouldn't have to go through this.

Stolen novel; please report.

Feeling frustrated by his inability to help, he wondered what to do. He knew that onis had supernatural abilities, but so far, he hadn't been able to do more than move his body uselessly.

The weather worsened and the woman shivered in the cold as she tried to protect her baby. She knew it was futile, as she realized he was hardly affected by the cold, a result of his blessing or the serum.

"Can this get any worse? I've already been blown up by a bomb, now I'm going to die before even growing up!" thought the baby, determinedly.

As the woman struggled against the snow, she spotted a dark cave on the slope. Despite being aware of the dangers, she thought it was better to face them than to freeze to death outside.

Entering the dark cave, the woman quickly prepared a fire. After some time, she stared intently at the fire, waiting for the storm to pass.

Unaware of the danger lurking in the cave, she eventually relaxed and fell asleep due to exhaustion.

Some time later, a large shadow approached her from inside the cave. It was a huge brown bear, ready to attack. However, upon noticing the baby's golden eyes, the bear retreated, recognizing him as the offspring of that two-legged creature. Instinctively, it knew it was facing a dangerous predator.

Alert and ready to act, the bear decided to retreat further into the cave and observe for a while longer, waiting for the two beings to leave.

At dawn, sunlight penetrated through the leaves and trees, illuminating the snow-covered landscape. Inside the cave, the baby and the bear remained extremely alert, showing no signs of fatigue.

Unsure if it was a hallucination, the baby began to notice something strange. The bear's skin seemed to become transparent, revealing muscles and blood vessels. Furthermore, everything seemed to slow down, as if in slow motion.

Despite the discomfort, the baby continued to observe. Over time, he realized that this strange vision allowed him to predict the bear's movements by the tension of its muscles.

"I never imagined I would use my knowledge of biology to predict the movements of a bear. Professor Greenwood, I hope you're proud of me, wherever you are!" reflected the baby, with a touch of humor.

"Incredible... where does this vision come from? It seems to affect the real world, it's not a hallucination. Is this the effect of the serum or the blessing?" he questioned.

Hours passed and they continued to stare at each other. When the woman finally woke up, she found the large bear watching her intently.

"Ahhhh... stay away, don't come near!" she shouted, brandishing a piece of burning wood and holding her son.

The bear, already on alert, retreated to the depths of the cave, startled by the woman's cries and the intimidating aura of the baby.

Seeing the bear move away, the woman breathed a sigh of relief and quickly tried to calm her racing heart.

"It's okay, it's okay now," she murmured to herself.

Startled and shocked, the woman packed up her belongings and continued on her journey.

The sound of snow being trampled echoed through the icy forest. Watching her son, who hadn't cried since they fled the village, the woman felt relieved to see that he was alive even in that cold.

"Sweetheart, you need to grow up and get strong to take care of your mother. You can trust me, things will get better!" she said with a smile.

Looking at the woman who fought so hard for him, the baby couldn't help but feel moved.

"I really owe her a lot. I thought I wouldn't get attached to the parents of this new life, but it seems I was foolish to think so," he reflected, feeling even more depressed by his apparent uselessness.

Not wanting to sadden the woman, the baby smiled and laughed at her, even though he didn't understand a word of what she said.

"Well... I haven't given you a name yet. I fought so much with that coward that I didn't have time to do it. Let's see, I'll call you Haru, which means spring. You were born in winter, but I want your life to be full of life, just like in spring. My name is Natsumi, Yukimura Natsumi, and you are named Yukimura Haru. Although I know you don't understand anything I say, I won't let anyone take you away from me!" declared Natsumi, looking lovingly at Haru.

And so she continued walking up the steep slopes and across the snowy ground. With a determination to cut iron and climb a mountain of blades.

"Good morning, Mrs. Saito. Came to buy the usual?" asked the vendor.

"Of course, this year's winter seems to have worsened. Put another half kilo of meat, I don't want to have to go out in this cold!" she replied, with a smile.

"Have you heard about the new resident who arrived last week?" asked the man.

"The one who rented the house next to the old church? Of course, I heard that she carried a very strange baby too. They say he was born deformed!" whispered the woman, as if it were gossip.

"Well... I heard she ran away from home because the baby wasn't accepted there!" gossiped the man.

"Seriously? What a shame. I hope she'll be okay. People are getting colder and less empathetic. Not even a baby is being spared!" said the woman, with a bitter tone.

"Better than in wartime. I almost hid in the mountains to avoid being forced to serve!" replied the man, reminiscing about the past.

In a somewhat decrepit house, Haru crawled across the tatami in search of something. After some time, pretending confusion, he found the tall shadow hidden behind the door.

A cry of happiness echoed through the house.

"Ah, you found me!" exclaimed Natsumi, radiant with joy.

Approaching Haru, she hugged him tenderly.

"Who's mommy's cute baby, who is it?" she asked, with a warm smile.

Held tightly in her arms, Haru once again questioned the meaning of his existence.

"I really need to grow up soon. I can't stand this life of pretense anymore," he pondered, feeling disturbed.

Since they arrived in that village, he had been forced to constantly imitate a baby to cheer up Natsumi.

After some time playing with Haru, Natsumi returned to the task of sewing the ordered clothes. After all, she needed to earn money to support Haru and herself.

Seeing that she had returned to work, Haru quickly crawled away, and when he was far enough away, he stood up on two legs and walked easily like a normal person.

"Finally, I can go back to training! What to test today? I think physical strength is fine!" he thought as he walked quickly to a secluded part of the house.

Arriving there, he quickly went to the backyard garden and found a medium-sized rock. Judging by its size and volume, it probably weighed between 5 to 8 kilograms.

Haru quickly approached the rock, stretched, and finally lifted it with extreme ease.

"Sigh... it seems I'll have to find something else to measure my strength. From what I've noticed, I've been getting stronger every day, and my body is also developing rapidly!" he sighed.

He conducted various tests over the weeks they stayed in the house. The first thing he noticed was that his nervous response and perception were extremely above normal. When entering the state he called absolute concentration, he could somehow speed up his thinking and nervous response by up to 4 times.

The speed, endurance, and strength of his body were also beyond that of a normal baby, but still within human limits. Furthermore, his concerns about solar weakness were misplaced.

"Just remembering the fear I felt when I put my hand in the sun... hisss... it wasn't a pleasant day at all, really!" he thought with a certain dread.

After failing to test his strength, Haru quickly returned inside the house. Arriving in the room where Natsumi was, he sat on the floor and began to watch her work.

Observing her work, Haru remained seated on the floor, as he always did, so as not to worry her. Every time he disappeared for more than 30 minutes, she went looking for him.

"Now I just need to test my supernatural powers and the ability to strengthen myself by eating human flesh!" he thought, with a touch of irony.

As for his supernatural powers, he had no idea how to activate them, since the anime didn't explain. As for human flesh, it wasn't a viable option morally, and also because he didn't have the capacity to kill someone.

"Eating human flesh to strengthen myself is not only a moral problem, but also a matter of time. After all, it takes a long time to increase my strength, in addition to attracting the attention of demon hunters," he reflected.

Determined not to be devoured by Muzan, if he was still alive, Haru felt a burning desire for more power.

Thus, even without knowing each other, Muzan gained a new enemy who wished to eliminate him above all else.