"To be honest, your house is a bit too big."
Haku glanced around the room where Ruri was and sat down without a hint of restraint.
"It is big, but it's a bit too quiet every day."
"That's true. By the way, are your parents home? Should I go greet them?"
Ruri shook her head and said, "No need. They're often not in the village. Without the talent to be ninjas, they have to do some small business trading outside. They only send a little money back every month."
Haku's eyelid twitched slightly.
Small business?
He wanted to ask if Ruri had misunderstood the concept of a small business.
"By the way, why did you come here? Although my house has a private training ground, it's too conspicuous and doesn't match your style of mystery."
Yesterday, Haku told her that he wanted to come over for something important.
"I want to conduct an experiment here. Do you have any hidden yet very sturdy empty rooms?"
An experiment? Ruri frowned, not understanding Haku's intention.
With Haku's level, Ruri didn't think he needed a large space to mess around.
The research funds and living expenses she usually gave him were carelessly handed over, just to make some noise, never expecting Haku to return them.
She never had any concept of money growing up.
"Because I think the commotion will be a bit big and somewhat dangerous, my lab at home is too small."
Hearing Haku's explanation, Ruri didn't pursue it further, guiding Haku through a corridor into an empty house.
She then opened a wooden board in the house, revealing a secret passageway leading underground.
Both sides of the passage had electric lights glowing.
At the bottom of the passage was an underground space of about fifty square meters, surrounded by and floored with hard stone slabs, capable of withstanding the impact of ninja techniques.
"Will this do? If it's not enough, there's another one next to it that's slightly larger, double the size of this one."
"It's enough, better than I imagined."
Haku was very satisfied with this enclosed space, far exceeding his expectations.
"I'll go back up first, call me if you need anything."
Ruri went back up alone.
Haku took out a sealing scroll, spread it on the ground, and formed seals with his hands. With a "bang," white smoke erupted from the scroll.
Along with the white smoke, a large number of research instruments appeared.
However, these research instruments were of relatively small sizes, which could be packed into a scroll.
Speaking of it, it was Ruri who taught him this ninjutsu for sealing things into a scroll for easy carrying.
Arranging the various research instruments neatly here, Haku began this experiment.
And this experiment was different from usual, accompanied by great danger.
If the experiment succeeded, the rewards would certainly be immensely generous.
◎
Towards the evening, as the sun set, Haku still hadn't come out of the basement.
In her room, Ruri finished refining Chakra in the afternoon, arranged dinner with the maid, and since Haku hadn't come out, she ate alone.
After finishing her meal, Haku still hadn't come out of the basement.
Ruri still didn't mind him.
Until midnight, while Ruri was having a good dream, the earth suddenly trembled.
Ruri's body also shook slightly, and with her keen senses, she sat up abruptly from the ground mat, scanning her surroundings.
Earthquake?
No way, Ruri immediately dismissed the thought.
The source of the tremor was very close to her, and the way the vibration was produced should be related to an explosion of objects.
Though it wasn't very obvious, she felt it.
Thinking of something, Ruri didn't have time to put on a coat. Wearing black tight innerwear, she slid open the wooden door and quickly walked toward the room in the other corridor.
Her destination was the basement of that house.
When Ruri reached the bottom, she saw a mess in the basement, with a huge crater in the center.
Even the hard floor that could protect against ninja techniques was blown into such a crater, and an unusual look appeared in Ruri's eyes.
Then she saw Haku, with his face covered in ash, who seemed to have been scared silly by the explosion in front of him.
In the explosion crater, there was a strong Chakra... yet it also felt a bit different, in short, a very intense aura lingered there, giving Ruri a sudden sense of being pounced on by a fierce beast, pressing heavily on her entire body.
Apart from that, there were only some completely destroyed research instruments, all beyond reuse, thoroughly wrecked.
"Why did you come down here?"
Haku snapped back to reality and asked a rather foolish question.
Ruri didn't mind any of that, and didn't feel angry about Haku making such a mess in her basement.
What she cared about was exactly what kind of experiment Hakushi was conducting that could blast the floor resistant to Ninja Techniques to this extent.
"What experiment are you doing?"
"Harnessing Natural Energy..."
Hakushi did not hide anything and answered honestly.
"Immortal Technique?"
Ruri gave Hakushi a surprised look.
"Yes, this is the hypothesis and steps of the experiment, but I can now also write the conclusion."
Hakushi took his notebook out of the Ninja Tool Bag.
After Ruri received it, she opened it to take a look.
Even though she could recognize every word, there were too many professional terms that she couldn't understand, ultimately making it impossible for her to comprehend what Hakushi was writing about.
"Did the experiment fail?"
Seeing the explosion here, Ruri assumed Hakushi's experiment had failed.
"Well, you could say it failed or you could say it succeeded. I successfully harnessed Natural Energy and merged it with ordinary Chakra, but I don't know the ratio they need to pair with or if other elements are needed to aid the fusion, resulting in this experimental accident. After the Natural Energy and Chakra went out of control, it was even more violent than I expected..."
Hakushi picked up a corner of a damaged research instrument and stood there lost in thought.
Ruri nodded in agreement.
Without a Jutsu to augment it, ordinary Chakra doesn't have this level of destructive power.
"What do you need next?"
For the first time, Ruri, who had never shown strong interest in Hakushi's research, wanted to support him.
"Money, a lot of money! And a more solid space!"
Hakushi was straightforward.
In his view, Ruri providing funds and space, while he handled the research, with both of them enjoying the final results was quite fair.
◎
Following Ruri into the room upstairs.
"Living here?"
Hakushi was a bit surprised at Ruri's sudden proposal.
"That's right, running back and forth is too cumbersome. Otherwise, you would only be able to come here on Sundays, spending too little time on researching Natural Energy, which would slow progress."
"Won't this arouse suspicion?"
Hakushi was concerned about this point.
"Not all the maids in my house are from the Uchiha Race. I can formally employ you at my house with an employment contract. Besides, who would focus their attention on a student from the Ninja School? Do you think the Anbu directly under the Hokage would deal with such trivial matters? Even if an investigation is needed, it's the job of our Uchiha Security Team."
Hakushi thought it made some sense.
After all, the experiments with Natural Energy really couldn't be conducted at his house.
His previous experiments were actually quite regular and not dangerous. Even if they were accidentally discovered, they could be explained away with words.
But not the Natural Energy experiments.
The things involved here were top secret and had to be kept confidential.
If Ruri employed him with a contract to work at her house, it was indeed a good way to divert attention.
The Anbu directly under the Hokage wouldn't have the leisure to monitor a Ninja School student, especially since Hakushi hadn't shown any hostility towards the village.
He was a true successor of the Will of Fire.
Even if in the unlikely event something seemed off, it would be a job for the Security Team, and Ruri, as a Uchiha Race genius, had her own backing.
The most important point was that he was broke.
In Konoha, there wasn't such a thing as a children's protection law; Hakushi had been kicked out of the orphanage at six to fend for himself. For an underage child to work for a living was... reasonable!
Ruri employing him through a contract was also a form of help between friends.
After all, he and Ruri were almost inseparable, and in many people's eyes, he and Ruri were great friends.
Assistance between friends is very normal.
This way, he would have enough time to conduct the Natural Energy experiments and enough confidentiality.
"By the way, how did you manage to summon the Natural Energy?"
Ruri asked the question that she cared about the most.
Although the Immortal Technique information she gave to Hakushi was merely the basics of Immortal Technique, she was curious about how Hakushi summoned the Natural Energy.
"Didn't you already see my previous notes? Speaking of which, it's actually quite simple; I don't know how the First Hokage guided the Natural Energy, but I guided Natural Energy from the root of Chakra, using the root system of Chakra to cast the bait."
"..."
"And speaking of the specific source of Chakra, it is actually related to our regular state of eating habits. Physical power is inseparable from food intake, supplementing carbohydrates, proteins, fats, glucose, etc. While Spiritual Energy is not just related to the soul, emotions can also influence a person's mental state, or status. Physical and Spiritual Power essentially originate from these, producing a chemical-like reaction with the human body, and after fusion and extraction, it becomes Chakra. Of course, this also involves a more complex human self-processing system, where there are variations in physical fitness, leading to... uh, did you understand that?"
"..."