Naruto: I'm really not an evil scientist!

While the Demon Slayer Corps' intelligence capabilities may not be all-encompassing, they are certainly top-notch.

When rumors of monsters, possibly ghosts, surface, it's natural to investigate.

As for the possibility of ghosts appearing, the Hidden Ones, as logistics and intelligence personnel, are most concerned about recent changes in the population.

If a large number of people go missing or even die, the culprit is very likely to be a cannibalistic demon, which will be a focus of attention. The Demon Slayer Corps will then dispatch swordsmen to further investigate and slay the demon.

But so far, no problems have been found in the area, no one has gone missing, no serious murders have occurred, and the area is even quite safe.

"Is that so?" Kagaya Ubuyashiki pondered for a moment, then said, "I understand the details. Let the team continue to carefully gather intelligence. Tell them not to be too reckless and that their safety is the top priority."

"Yes, my lord!" Yin seemed very moved, then asked, "Should we notify the swordsman closest to the area to assist in the mission?"

“No, not for now.” Kagaya Ubuyashiki shook his head. “Even if there are team members who know the relevant information, please ask them to be patient and not to act rashly.”

……

Although he believed that no opportunity to eliminate demons should be missed, he would not allow his child to recklessly rush in without knowing the full story.

He always regarded all the members of the Demon Slayer Corps as his own children and hoped that they would be safe and sound.

Moreover, those so-called underground monsters are not necessarily man-eating evil spirits.

The Ubuyashiki family is a noble family with a history of over a thousand years. They share the same ancestor as the demon king Muzan Kibutsuji and have intermarried with the priests for generations, thus possessing knowledge of many secrets.

However, due to Muzan's evil deeds, the Ubuyashiki family's bloodline was also cursed.

The lifespan of this clan became very short, and their children were all weak and sickly, especially the boys. Moreover, there was an increasing number of infant deaths.

Even if one survives, as they age, they will gradually experience a series of physical deteriorations such as blindness, disease, and disfigurement, which will rapidly lead to death.

To alleviate this phenomenon.

Chapter 401 The Underworld Has No Underworld Oversight

In order to prevent their bloodline from being completely severed, the Ubuyashiki family followed the advice of the shrine priest and married girls from the priest family in every generation.

Although this method extended the lives of future generations, none of them managed to live to the age of 30.

This has always been a source of anxiety and regret for Kagaya Ubuyashiki.

The Ubuyashiki family possesses a shallow precognitive ability, or rather, an extremely strong premonition. This ability is mysterious and profound. Although it is not as clear as the prophecy of Master Doppi in the JOJO world, nor as insightful as the Great Toad Sage of the Ninja World, it is still a unique phenomenon.

Kagaya Ubuyashiki would occasionally have a flash of inspiration and feel that something might have nothing to do with ghosts, and often it turned out to be true.

This is not the crude "I think" of the green-skinned orcs, but rather closer to the divine revelation received by Joan of Arc, or the spiritual vision of a witch, only a lower-budget version.

After all, this world has a certain degree of magical setting. In addition to the unique combat system of breathing techniques, there is also Sakonji Urokodaki's amazing mental suggestion, as well as the souls that wander like earthbound spirits. Even the concepts of the underworld and reincarnation are deeply rooted in people's hearts.

Moreover, the underworld in this world is not supervised by the underworld officials, nor are there Black and White Impermanence to restrain souls. Whether a soul chooses to stay in the human world or reincarnate is entirely up to its own will.

"I understand, my lord." Yin nodded, indicating his understanding.

……

Cherry blossom petals drifted down in the courtyard, adding a touch of gentle beauty to the tranquil space.

Hiruko, a ninja known for his scientific research, sat cross-legged under a cherry blossom tree, his hands constantly clenching as if grasping something invisible, his eyes flashing with an eerie green light.

If you look closely, you can even see the data characters flowing in his pupils, which is a symbol of his wisdom.

"Interesting~"

Hiruko exhaled softly, and a dark, gloomy hole opened up in front of him, from which a chilling current, imperceptible to ordinary people, surged forth.

This is Yomotsu Hirasaka, a technique at the level of Bloodline Limit, the ultimate space-time ninjutsu belonging to the Otsutsuki clan.

The Book of Formations once commented: "Appearing at the gates of the underworld in less than a moment!"

Despite the book's exaggerated claims, Yomotsu Hirasaka is actually just a black hole that opens out of thin air, similar to a portal, allowing the caster to travel within the same space or freely enter and exit between the real world and other dimensions.

At least in the ninja world, Kaguya Otsutsuki couldn't directly use this skill to rush into the Pure Land and drag her unfilial son out for a beating. She only used it to escape, evade, shift the battlefield, splash acid, and shoot bones...

But now, Hiruko has done it; he has opened the gates of this world's underworld with Yomotsu Hirasaka.

As a research ninja, his soul is inherently very sensitive to time and space. As time goes by, the more knowledge and information he acquires, the deeper his understanding of the world and time and space become, and his abilities naturally increase accordingly.

Feeling the chilling wind and turbid current rushing towards him, Hirugo laughed.

He was all too familiar with that ghostly aura, and that presence that bore a resemblance to the Ninja World's Pure Land of the Underworld.

"It seems to be another underworld that blends Japanese mythology with some Buddhist elements. Fortunately, there's no demon king in charge, nor any gods, Buddhas, or Yama in charge." Hiruko's eyes flashed with countless data points, a unique analytical method he used as a research ninja. He had completed the initial investigation and said with a smile.

It seems that although this world is supernatural, there are no cases of powerful individuals monopolizing the public resources of reincarnation for their own private use.

If that's the case, then he won't hold back.

Hiruko, in the Naruto world, encountered the Pure Land, toyed with souls, trampled on death, and desecrated the cycle of life and death. In the process of fulfilling people's dreams, she also created many crudely crafted pirated versions of the Netherworld.

In the W world, countless dark spaces were created near the roots of the Divine Tree, transforming them into artificial underworlds. These spaces guided souls tainted by chakra back to the underworld, and White Zetsu were made into messengers of impermanence to imprison souls lingering in the human world and return them to the underworld.

Now that the Demon Slayer world has a rare natural underworld, Hiruko naturally wants to study it carefully.

To put it in a more fantastical way, he wanted to comprehend the most powerful laws of reincarnation, just as he comprehended the laws of Earth in the W world and copied Earth as his foundation. He also wanted to copy this underworld.

He will also take over this unclaimed land, and after he has thoroughly exploited it, he will remodel it, turning the entire underworld into the shape he desires.

Although the underworld in this world is a Schrödinger's cat-like state, seemingly an illusion, a non-material world, and not a real physical space like the Soul Society, it is still real and can guide the souls of the dead to reincarnation.

Ordinary people's bodies cannot enter, and ordinary people's souls cannot affect this vast world. However, Hiruko can be digitized and then mimicked into corresponding life forms. This is not a difficult task for him, a scientific research ninja.

Moreover, even without transforming his form, relying solely on chakra, the Six Paths could connect the Yin and Yang realms with a single strand of chakra, a feat he could easily accomplish now.

After experiencing the W world, Hiruko gained a lot of insights into how to connect with special worlds and improve his synchronization rate with them.

He is now able to compile space, and even at a considerable cost, rewrite the rules to some extent.

If there is anything in this world worth lingering in and coveting, it is only this dark and unclaimed land, and the vast and boundless universe.

The value of this world itself far exceeds that of Muzan, this failed attempt to evolve into the ultimate life form.

Of course, Muzan Kibutsuji is not without merit.

Demons are creatures that mutate from humans. They possess extremely strong regenerative abilities, long lifespans, powerful bodies, and a special ability called Blood Demon Arts. They can also infect and spread their race through blood.

If a monster like a demon, seemingly created by biological science, can solve the mystical flaw of fearing sunlight, it would be very meaningful for Hiruko.

Because the Oni race has a long lifespan, this advantage alone is enough for Hiruko to value and study it.

Not to mention that the demons in this Japanese worldview still have some potential for growth. Suika Ibuki and Yuugi Hoshiguma from Touhou Project are characters that Hiruko loves.

Even the Otsutsuki clan, besides having elements of Dragon Ball, also draws some parallels to the oni clan in Japanese mythology.

Hiruko has now been freed from the lifespan limit and become an immortal being, but many of his relatives, friends, and even subordinates need more methods to prolong their lives.

Although Hiruko had already analyzed the Otsutsuki's genetic technology, as long as he had enough chakra, he could refine powerful pills that would allow people to stay young forever, or even live forever and evolve into higher levels of life.

However, even someone with a massive amount of chakra like Kaguya craves more chakra, and Hiruko also needs more chakra to evolve to a higher level. It is impossible for him to share his chakra with others without limit.

The immortal cultivation method he created by combining qigong, the mysteries of chakra, the energy conversion method of the divine tree, and the combination of natural energy and the secrets of sealing techniques is still called the immortal way. It is an extremely powerful technique with all sorts of incredible effects.

However, while the path of immortality can increase vitality and prolong life, he was unsure whether it could truly enable cultivators to transcend mortality through this method.

After all, even for him, the developer, it would be difficult to reach his current life level simply by relying on this technique without using cheats.

People's physical constitutions cannot be generalized. Some people can forcibly raise the upper limit of their cultivation techniques, while others can lower the lower limit of cultivators. There are always a few useless people in a group.

Therefore, Hiruko will conduct in-depth research and modification on those who do not evolve into humans, such as vampires, pillar men, oni, Ōtsutsuki, data humans, and monsters, as a way to leave a way out for those close to him.

However, Hiruko did not have the idea of ​​directly setting out to capture Muzan, this inferior product.

In his mind, the underworld of this world is the most valuable. He is also quite interested in Yoriichi Tsugikuni, and it's not bad that Nezuko and Tanjiro both have the potential to evolve into demon kings who are not afraid of the sun.

Then he became interested in Sun Breathing and Tamayo, who already had some knowledge of demons, and finally Muzan, the guinea pig.

Muzan's priority is relatively low. Before he fully controls Yinming, he's the kind of person you'd just let go of if you don't encounter him, and grab if you do.

At this stage, Tanjiro's entire family has been sacrificed to the heavens, leaving only his sister who has been transformed into a demon. He himself is currently undergoing training with a mentor at Mount Sagiri to learn the Water Breathing technique.

These days, besides researching how to open the Underworld, Hiruko also plans to send a large number of White Zetsu to search for the so-called Blue Spider Lily after draining the Underworld, and also to find the whereabouts of the First Pillar Tanjiro, since Tanjiro's nose is quite interesting and mysterious.

……

Kanroji Mitsuri, carrying groceries she had just bought from the market, walked happily down the street, humming a little tune.

Although White Zetsu can fly and dive to grab all kinds of fresh ingredients, she still goes to the market after being cooped up at home for a long time.

After all, during this time, in addition to practicing with Hiruko, she had also been staying at home to learn some cultural knowledge taught to her by Hiruko to improve her literacy, until her eyes were blurry from studying.

Mitsuri is quite talented. In the original story, after failing to find a boyfriend through matchmaking, she chose to join the Demon Slayer Corps in order to find a man who would truly accept her and a good husband who was stronger than her and could protect her.

After joining the Demon Slayer Corps, she was first taken in as a protégé by the Flame Pillar Kyojuro Rengoku and learned Flame Breathing. Later, she independently developed a derivative of Flame Breathing—Love Breathing—and became the Love Pillar.

In the original story, it only took half a year for Mitsuri Kanroji to go from joining the Demon Slayer Corps to becoming a Pillar, so there is no doubt that Mitsuri possesses extremely high talent.

However, this is not an exaggeration. After all, there is a genius in the Demon Slayer Corps who became a Pillar after only two months of wielding a sword, and its progenitor Yoriichi Tsugikuni was a powerful man who was destined to stand at the pinnacle of humanity from birth.

Therefore, Mitsuri was able to learn the Ripple Breathing Technique taught by Hiruko in a very short time and understand the various wonderful uses of Ripple.

Afterwards, with a portion of his chakra given to him by Hiruko, and with the supply of various miraculous pills, tree fruits, and spirit stones, he successfully cultivated Hiruko's modified "Sage Path".

Is that her?

"That's right, she's the owner of that weird grocery store."

"So big..."

"What did you say?"

"No! I mean, what a lovely girl! She's already married? Oh, I'm heartbroken."

"Heh~"

"What kind of look is that?!"

"Lust is a double-edged sword; be careful not to get eaten by a female ghost."

"Impossible! How could such a cute girl be a ghost! Besides, she can walk in the sunlight, that's proof!"

"She's frequently in contact with burrowing monsters, so she's probably a monster herself. Who knows what she might be like..."

"You're just arguing for the sake of arguing!"

At the street corner, a ramen vendor and a customer, who were using a mobile cart to sell ramen, were both keeping a close eye on Kanroji Mitsuri while whispering to each other.

"Those two idiots!" Besides these two, all the vendors on this street are actually members of the Demon Slayer Corps in disguise.