Father of Education

"Yo, Tanjiro." Isao nodded, then looked at the young man beside Tanjiro. "Who is this?" 

"He is my friend, Inosuke Hashibira." Tanjiro smiled softly since it was great that he got to know many kind people when he had become a Demon Slayer. "Inosuke, he is Iinuma-sama. He is my benefactor and the strongest Demon Slayer." 

"Benefactor?" 

While Tanjiro didn't realize it, Inosuke's body was slightly stiff when he saw Isao, and he didn't doubt Tanjiro's words when Tanjiro told him that Isao was the strongest Demon Slayer. While he had met many strong Demon Slayers, such as Sanemi and other Hashira, the feeling that Isao gave was completely different. 

Once again, if the others were like the light of a candle or bonfire that warmed many during the cold night, Isao was like complete darkness that erased all the light and warmness, yet instead of giving a complete coldness and terrorizing everyone, his darkness made people feel comfortable, reminding anyone of when they were still inside the womb of their mothers where it was complete darkness, yet filled with kindness. 

However, if one let his guard down due to this, then they were wrong, and it was because of this that Inosuke, who had always been rude, had his body tense all the time when he saw Isao since he was sure that as long as he said something wrong, he would be swallowed. 

Why did Inosuke think so? 

It was because of his instinct as one who had been living in the wild from his childhood and how powerful his sense of touch was. 

Like Tanjiro, who had a strong sense of smell, Inosuke also had a powerful sense of touch, which made him able to feel the slight vibrations in the air.

Naturally, whether it was Tanjiro or Inosuke, the two quickly noticed how strong Isao was, unlike their third friend, Zenitsu, who was a skirt-chaser and helpless idiot, especially when he kept doing something stupid even if his grandfather's figure, Jigoro Kuwajima, committed seppuku in the original story. 

However, unlike in the original, with Jigoro around, it was probably impossible for Zenitsu to do something stupid. 

Yet, even if Zenitsu did so, Isao didn't care since he didn't think they would meet again in the future. 

On the other hand, without knowing what Isao was thinking, Tanjiro explained how Isao had helped his family while hiding the fact that Isao had tried to deceive him beforehand. 

Tanjiro's IQ and EQ weren't low, and he knew what he should and shouldn't do, especially when his little sister and mother were under the care of Isao. 

Isao also didn't stop Tanjiro, letting him explain how much help he had given to Tanjiro's family. It didn't mean that he wanted Tanjiro to repay him, but while Inosuke wasn't stupid, Inosuke was still affected by his animal-like thinking, and Inosuke often did something rash. 

However, with the reminder of Tanjiro, Inosuke shouldn't do something stupid, right? 

Still, understanding everything, Inosuke knew that Isao was the strongest Demon Slayer, and usually he would try to challenge Isao, but—

"Let me introduce myself again. My name is Iinuma Isao. What about yours?" 

Isao stretched his hand toward Inosuke, but Inosuke looked at his hand for a while before he sniffed it like an animal, which sniffed something that it had never seen before. 

"....." Tanjiro. 

However, Isao was calm and reached Inosuke's hand, then shook it firmly. "When someone does that, you should hold the other's hand firmly like this, but not so strong that they will feel pain. It is also the most common method for one to get to know each other." 

When his hand was pulled, Inosuke usually would pull his hand away, showing his cautious side like an animal, who was wary of something that it never knew, but unexpectedly, he could do nothing and he just let his hand held firmly by Isao. 

'This guy... what's wrong with him?' 

In Inosuke's eyes, Isao was like a mix of various things, which made him wary, relaxed, easy, complex, and secure, yet frightened. All of those emotions were felt at the same time, which confused him. 

Yet, for one thing, Inosuke could do nothing and just obediently shook Isao's hand since he could tell that Isao sincerely tried to teach him. 

[You have acquired Inosuke Hashibara's DNA.]

[Do you want to absorb it?]

With all of this, Isao knew that it was time to end Muzan. 

"Isao-kun?" 

Turning his head, Isao saw Shinobu was there. "Yo, Shinobu." 

"When did you come? Why didn't you tell me?" 

"I just happened to go back from Kagaya's house. Anyway, could you prepare tea? I have brought some snacks with me." 

Shinobu was speechless since Isao treated this place like his home, so she didn't care much and prepared tea for him. 

"You two will stay for a while, right? Join me to have snacks." 

Tanjiro and Inosuke looked at each other before they nodded. 

So, along with all the people present, Isao took out all the souvenirs that he had brought from Tokyo and had a small feast with everyone. Naturally, the main character of this feast was chocolate, something that they hadn't tried before. 

"S-Sweet! So sweet!" Inosuke seemed to be dumbfounded when he tasted the sweetness of the chocolate for the first time. 

"You can't overeat! It isn't good for your body!" 

When Shinobu saw many of those young people wanted to eat those sweets, gorging themselves with them, she directly scolded them, causing all of them to lower their heads, but their eyes were full of desire. 

Isao only watched all of this with a smile, sipping his hot tea, thinking that Shinobu would somehow become a strict mother in case she had children in the future. 

Scolding them for a while, Shinobu then looked at Isao, who sipped his tea calmly and asked, "How long are you going to stay here?" 

"I will go back after this." 

"I-I see..." Shinobu felt disappointed somehow, but at the same time, she quickly shook her head. 

Why should she feel disappointed? 

This bastard was her older sister's man! 

Why the heck should she feel like this? 

Still, Isao didn't care much about Shinobu's complex feelings. Instead, he looked at Tanjiro, then Inosuke, and then asked, "Say, have you two thought what you will do after Muzan is defeated?" 

"Hmm?" 2x

Cleaning up the sweets in their mouths with tea, Tanjiro and Inosuke were quickly attracted by Isao's question. 

"What do you mean, Isao-sama?" Tanjiro was confused by Isao's question. 

"In case Muzan disappears, erased from this world, the Demon Slayer Corps will disband, and have you thought about what you plan to do?" Isao asked. 

"I... will try to find a cure for Nezuko," Tanjiro said. 

"After that? When Nezuko is cured, what will you do?" Isao asked.

"Hmm..." Tanjiro thought for a while, then said, "I am not sure. I will probably return to how I used to be." Like before, he would sell coal since it was the only skill he had. 

"What about you, Inosuke?" Isao looked at Inosuke. 

"Hmm..." Inosuke seemed confused, then said, "I will follow Tanjiro!" He didn't know what he would do, but it definitely wouldn't be wrong to follow Tanjiro. 

"Then, you might as well enter my school," Isao said. 

"Enter your schools?" 2x

Tanjiro and Inosuke were dumbfounded. 

Or rather, those who were present were dumbfounded. 

Isao nodded. "I thought of opening a free school where everyone can learn the knowledge necessary for the future. Naturally, it will be free. If you don't have anything to do, then you might as well come to my school to study so your future will be broader." 

Isao then looked at Tanjiro and said, "Moreover, if you learn, you might be able to find a way to solve Nezuko's problem by yourselves." After saying that, he looked at Inosuke and said, "Mountain is too small for you. You should see the world, which is far more vast than you have imagined." 

"....." 2x

Tanjiro and Inosuke couldn't say anything since they had never thought of going to school. 

"Well, you can only do this when Muzan disappears, so work hard and don't die." 

"We will!" 2x

His words brought hope to the two, and they wished to end Muzan and then enter the school that Isao planned to create. 

While Tanjiro thought of learning so he could solve Nezuko's problem and bring a bright future for his family, Inosuke thought about Isao's words, which made him eager to learn so he could see how vast the world was. 

With that determination, the two quickly excused themselves and prepared to train harder since they had to become stronger so they could defeat Muzan and stay alive in the future. 

Watching how excited the two youths were for education, Isao smiled, thinking that it was great to do something good. At the same time, the value of education was much different in this era than in the modern era. The wish of everyone to learn was so high that he was amazed. 

"Are you planning to open a school?" 

When Tanjiro and Inosuke left, Shinobu couldn't help but ask. 

"Yup." Isao nodded. "I have a lot of money, after all. It doesn't matter if I use some of them to give everyone a free education. Moreover, I don't have a long time to live, so I want to leave many traces before I am gone from this world, and making everyone in this country able to learn is one of my dreams." 

This was probably the reason why Kagaya was quite tolerant of Isao's relationship with his wife.

After all, as Isao had opened the Demon Slayer Mark, he would die before he reached 25.

Even if Amane got pregnant with Isao's child, it didn't matter. 

Or, probably because as long as Isao could join the Demon Slayer Corps and erase Muzan, Kagaya didn't care about the price at all. 

Either way, Isao knew that he shouldn't make the wife of someone pregnant in the future so his situation wouldn't be so complicated. 

"Y-You won't die! I will make sure of it!" 

Isao's dream to make everyone able to learn was a wonderful thing, and Shinobu wished to be his support. At the same time, she definitely wouldn't let him die after 25! 

Isao only smiled and didn't plan to say that he wouldn't die, but he knew if he pushed Shinobu now, she would be obedient to accept his advance. 

Yet, as a good person, how could he use such an underhanded technique to take down Shinobu?

However, if Shinobu pushed him down, Isa could only accept it. 

Nevertheless, when everything was done, Isao planned to take down Muzan as soon as possible. There was no need to wait any longer, so after he returned to Tokyo, he went to Tamayo, who seemed to be in a weird mood when she saw him, but it didn't matter since there was something that he wanted her to do.

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Just to ask, have you watched "Tokyo ESP" or "Engage Kiss"?