Haganezuka

After finishing his meal, Muzan arrived at Yanagisawa Noriyuki's place.

As for Yoriichi, he seemed to have come to terms with things. He took a Nichirin Blade and a regular sword and set off to wander the world, helping Muzan by chance to kill any Half-Demons he encountered along the way.

He wore two swords at his waist, like a dual-wielding swordsman.

Muzan was displeased with Tamayo's research progress.

How many years had it been!

She still hadn't figured out how to overcome Wisteria Flowers!

So, he decided to bring Yanagisawa Noriyuki over to help Tamayo with her research.

Yanagisawa Noriyuki was in the middle of a leisurely afternoon nap when Muzan's arrival startled him awake. He rolled over and groggily climbed off the tatami mat, only to see a Demon King as large as that standing before him.

He instantly sobered up.

He hadn't seen Muzan in decades, and now the Demon King suddenly appeared before him.

"Let's go!"

Seeing that he was awake, Muzan yanked him out of his futon and, grabbing him, instantly appeared at Tamayo's home.

Tamayo was also taking a nap and was startled awake by Muzan, whom she hadn't seen in decades. She jolted, and like a ghost, he held another ghost and stood outside her window, watching her leisurely.

Tamayo got up, threw on a coat, pushed open the door, and looked at Muzan:

"Boss, what are you doing here again?"

Muzan put Yanagisawa Noriyuki down: "Your research is too slow. I've found you an assistant."

Yanagisawa Noriyuki finally landed, tidied his clothes, extended his hand, and smiled: "Hi..."

Tamayo: "..."

Alright, it was her fault. After all these decades, she still hadn't figured out why Wisteria Flowers harmed and repelled demons.

Muzan looked like he was entrusting them with a great responsibility, solemnly patting both their shoulders: "Good luck! I have high hopes for you both! Don't slack off."

With that, he vanished from the spot.

The effect of Wisteria Flowers on demons was at most weakening and poisoning; they couldn't inflict fatal damage. Plus, he was no longer afraid of the sun, so they couldn't cause much trouble.

Besides, Tamayo had told him before that if he was truly afraid, he should eat Wisteria Flowers himself for a few years, and he would naturally overcome it. If he was optimistic, he might not be afraid after just a few times.

It would just be a very painful process.

Muzan didn't want to inflict unnecessary suffering on himself. Let Tamayo pull her hair out!

His best assistant had already come over to his side, so why waste it?

After giving his instructions to the two, Muzan began to focus on another matter.

One of his subordinates had already discovered someone who seemed to be Haganezuka.

In the Edo area, a child lived with his father, who was gravely ill and bedridden.

The child survived by stealing and had been caught and punished many times by the magistrate. However, due to his young age, he hadn't been killed.

If Muzan's subordinates hadn't happened to pass by and overhear rumors, they wouldn't have found him.

Looking at the description, it was almost identical to the story of Akaza's human life mentioned in the original work.

By the time Muzan arrived, the child, who had been stealing everywhere, was branded a criminal and was already notorious. Muzan didn't have much trouble gathering information.

The child's name was indeed Haganezuka!

"That guy lives here. What are you looking for him for?"

Haganezuka's neighbor pointed to his house, looking at Muzan quizzically.

Muzan smiled: "I'm a doctor. I heard there's a child here whose father is seriously ill."

"Fine, must be overflowing with kindness..."

The person muttered, shook their head, and left.

Another passerby happened to see Muzan, a stranger, seemingly looking for Haganezuka. A woman walked over with a worried expression, clearly not having heard Muzan's words:

"Hello? Are you looking for that child, Haganezuka?"

Muzan glanced strangely at the old woman walking towards him: "Yes, what's wrong?"

The old woman sighed, instinctively assuming Muzan had been stolen from and had come to demand his belongings back. She advised:

"That child's father is seriously ill, and he's always trying to earn money to buy medicine for his father. He's also a pitiable person, so please don't blame him too harshly."

Muzan understood her meaning:

"Don't worry, I'm a doctor. I just want to see if I can treat his father."

The old woman breathed a sigh of relief upon hearing this and then hurried to lead Muzan to Haganezuka's house.

Pushing open the door, the courtyard was empty. Through the half-open wooden door, they could see a man leaning against the wall, coughing violently.

The old woman quickly went over and poured him a glass of water, introducing him at the same time:

"This is a doctor. He came specifically to see you."

The person's coughing finally stopped, and they looked weakly at Muzan.

Muzan nodded, a form of greeting, and moved closer to examine them.

He had learned a lot of medical skills from Tamayo and Yanagisawa Noriyuki, and with their memories, he was capable of treating illnesses. Yanagisawa Noriyuki's own ability was, in fact, healing.

After a thorough examination, Muzan could roughly confirm it was just bronchitis, but due to long-term neglect and lack of money for medicine, it had become severe, making treatment even difficult.

It wasn't difficult, really. Muzan could solve it with a single healing spell.

However, for his own purposes, Muzan decided to talk to Akaza first.

After the old woman left, Akaza quickly returned home with a small bag of medicine.

At this moment, Akaza's clothes were made of rough, grey-brown rags, barely stitched together, more like a single piece of cloth. A black cloth was tied around his waist to hold it in place.

The clothes were covered in patches, the edges already frayed, and the black cloth at his waist was tattered. The cloth tied to the wooden sandals on his feet showed signs of multiple repairs.

Scars from beatings could be seen on his wrists, ankles, and around his neck.

His short black hair was a bit messy, but he held the medicine with a smile on his face.

When he saw the stranger sitting in the house, his first reaction was caution.

Muzan offered a gentle smile, "Hello, I am a doctor."

Akaza breathed a sigh of relief, then hesitated, wanting to ask the doctor to examine his father properly and treat his illness, but fearing he wouldn't be able to pay the fee.

Muzan continued, "I want to treat your father, and I won't charge you. However, I need to speak with you alone."

Muzan hoped to turn Akaza into a demon, but he wouldn't force him. His current actions were more out of pity for the characters in the original story.

He felt that since he had come to this world, he should help those characters he felt pity for and whose fates tugged at his heartstrings in Demon Slayer.

Closing the bedroom door, Muzan stood in the yard and looked at Akaza, saying:

"I just diagnosed it. Your father's illness is merely bronchitis. It shouldn't be difficult to treat, but because it's been neglected for too long..."

Akaza heard this and hurriedly asked, "Is there a way to treat it?"

Muzan nodded, "Yes, but it's a bit troublesome."

"As long as you can treat my father, I'll do anything!"

Akaza, barely a teenager, stood before Muzan and said anxiously.

"No matter how much it costs, I'll find a way!"

Muzan smiled, "Don't worry, you don't need to pay. I can prepare the medicinal ingredients."

Akaza's expression changed in surprise, then he asked, "Then, what do you need me to do?"