Given its importance and dangerous nature, Ryuji constructed three layers of walls and checkpoints around the Specific Gravity System, stationing five hundred knight puppets to guard it.
November 20th.
During the experiments on the Kagero Clan's special constitution, Ryuji tried every method, obtaining fifty-three different types of poison, but still hadn't gotten the one that inhibited plant transformation.
Simultaneously, with over five experiments daily, Ryuji amassed a large amount of data on the tumor's operation.
November 21st... to 24th.
Inside the laboratory.
Ryuji and Kana sat facing each other, expressions solemn, atmosphere heavy.
The two looked at each other, neither speaking.
After an unknown length of time, Ryuji broke the silence.
"Have you really decided?"
Hearing this, the girl took a deep breath, her bright eyes growing even more resolute.
"I'm ready."
"This is your decision. I will respect it. I'll go prepare the antibodies now."
Ryuji sighed, stood up, and walked toward the cold storage chamber inside the laboratory.
Through continuous trials these past days, he had obtained one hundred eighty different types of poison, including the one that inhibited plant transformation.
This should have been a cause for celebration, but the poison Kana produced had started repeating.
This meant Ryuji had tried all methods, recording all possible changes the tumor could undergo except for one specific situation.
Charm-Poison Body… this was the Kagero Clan's name for their special constitution.
With the data in hand, Ryuji was eighty percent confident of successfully solving the Charm-Poison Body problem.
But lacking the most crucial piece of data might lead to complete failure, even Kana's death.
Ryuji had explained all the circumstances to her, letting her make her own choice.
Should they begin treatment now, or collect the final experimental data before treatment...
As for the option of her returning to the clan's homeland to retrieve the recorded data scrolls… that was never considered.
The Planetary Engines were nearing completion.
Once the Planetary Engines were installed, he would go to Konoha to complete the Wood Release Shinobi matter. Afterwards, he still needed to create the Sage Body for Gin or himself.
After that, there was research on Konan's reincarnation issue, and so on...
There simply was no time to solve Kana's Charm-Poison Body problem.
Unless she could patiently wait a few years.
Wait until Ryuji finished his current tasks, then solve it for her.
In Ryuji's opinion, since so many years had passed already, waiting a few more years shouldn't matter.
But Kana couldn't wait.
The threat of clan extinction pressed down on her like a mountain. Until resolved, she couldn't feel at ease.
Who knew what the situation would be in a few years?
What if she or Ryuji died accidentally?
What if Ryuji had even more tasks piled up?
What if...
There were too many uncertainties with waiting years. She couldn't afford to wait.
Of course, these were objective factors.
The direct factor was that the research data recorded by the Kagero Clan over hundreds of years probably wouldn't help Ryuji at all.
Kana initially thought Ryuji's research was similar to the clan's centuries of research. But truly participating in the experiments and seeing the dense, completely incomprehensible data, she realized the two weren't the same thing at all.
The data recorded by the clan over centuries probably wasn't as much as what Ryuji recorded in a few days.
Precisely because of this, Kana resolved to proceed with the final experiment.
Of course, there was another major reason.
That was, during these short eleven days of experiments, she had been teased hundreds of times... her inner desires were long unbearable.
Even though Ryuji was purely conducting research work, she couldn't endure it anymore.
…
Arriving before the cold storage chamber, injecting the prepared antibodies into his body... The Charm-Poison was called unsolvable because it produced different poisons based on different situations.
Generally, to create relevant antibodies or antidotes, one needed to understand the toxicity beforehand.
But by the time one understood the toxicity, the next poison had changed, making it unsolvable.
But Ryuji's research over these ten-plus days obtained hundreds of deadly poisons. Antibodies developed by studying these poisons' properties were sufficient to immunize against most poisons in the world.
But even so, it wasn't foolproof.
Because the Charm-Poison Body produced different deadly poisons based on different situations.
Kana had never had intercourse before, so they didn't know what kind of poison would be produced during actual intercourse, or whether his researched antibodies could immunize against it… it was unknown.
Therefore, he prepared backup bodies.
If an accident occurred, he would promptly change bodies.
As for why not use protective measures...
Honestly, such things didn't exist.
Although they could be researched, Ryuji had never considered them before.
Moreover, if they couldn't reach the final base, the experiment would be meaningless.
Feeling the antibodies take effect in his body, Ryuji turned to look at the girl.
"Kana, are you ready?"
"Mm."
The girl nodded almost imperceptibly, lowering her head with a blushing face.
"Then let's begin!"
Ryuji slowly walked over and embraced the girl.
…
Several hours later.
Ryuji, sweating profusely, slumped onto the floor. His entire right shoulder down to his chest and abdomen had turned blue-black.
He had been poisoned in the end.
Although, due to the antibodies, there was no mortal danger, his entire right side of the body now had no sensation. Through the Observation Device's detection, the cells on the right side had necrosed.
If the antibodies hadn't taken effect when the poison spread, producing immune cells within his body...
He probably would have changed bodies by now.
"Are you okay!?"
Kana sat on the observation instrument's platform, looking at Ryuji with some self-reproach and worry.
Initially, he hadn't been poisoned.
"It was my mistake." Ryuji gasped heavily. "I didn't anticipate the same method... If that's the case, then the previously obtained experimental data is far from sufficient."
At this point, Ryuji felt fortunate.
"Fortunately, you didn't choose to proceed with the risky experiment. Otherwise, failure and death would have been one hundred percent certain."
The same method, according to different degrees, could also produce different poisons. Calculating with mathematical formulas, the data he currently had probably amounted to less than one percent of the total deadly poisons the Charm-Poison Body could produce.
Operating based on such experimental conclusions would be almost certain death.
Hearing Ryuji's explanation, Kana also felt relief.
But now she was more concerned about Ryuji's physical condition.
If something happened to his body, no one could help solve her Charm-Poison Body problem.
Moreover, they had this kind of relationship... With good luck, she might even conceive his child.
Although he only saw this as work, she didn't... mind.
Perhaps!
"Necrosed cells can only regenerate if removed, but my body doesn't have that strong life force. If I really cut off a small half of my body, I probably wouldn't last long before dying, right?" Ryuji said somewhat self-mockingly, "Does this count as risking my life for work?"
"Uh..."
Kana felt somewhat awkward and also disappointed.
She had thought Ryuji would say: risking his life for a woman.
But it was for work.
Although she recognized from the start that everything he did was for work, deep down there was still a sliver of hope.
Hope that the man who had relations with her would develop some feelings for her.
But Ryuji's words now made her give up completely.
'This man truly, truly had not a shred of feeling for me.'
Thinking this, Kana discarded the last shred of fantasy in her heart, rationally viewing the problem.
She took a deep breath and said seriously, "So, there will need to be many more experiments afterwards?"
"Correct." Ryuji nodded, looking at her with a half-smile, "The Planetary Engines will be completed in at most another month. By then, I'll go to Konoha. That means all remaining experiments must be completed within this month. Can your body handle it?"
"You should worry about yourself!"
Hearing this, how could Ryuji hold back? He immediately applied Medical Ninjutsu to treat this pitiful patient.
…
Time continued to pass.
November 26th.
Research on the Charm-Poison Body had been conducted dozens of times, collecting over sixty new deadly poisons.
Three hundred Planetary Engine thrusters had been produced.
Ryuji also modified the worker robots with propulsion flight devices and began formal installation.
November 30th.
Kana, as the experimental subject, indicated her body couldn't take it anymore and needed rest.
Ryuji brought out supplements obtained from past check-ins, and the experiments continued.
December, the weather gradually turned cold.
Kana indicated her hands and feet felt icy.
Ryuji brought out a higher grade of supplements. The girl instantly felt warmth, and the experiments continued.
December 6th.
Over a thousand Planetary Engine thrusters had been produced, three hundred installed.
Because installation positions were pre-calculated scientifically, they could now fly at a crawling speed.
December 15th.
Three thousand Planetary Engine thrusters had been produced, two thousand installed.
As production experience and technical knowledge accumulated, production speed accelerated.
Research on the Charm-Poison Body also continued.
So far, Ryuji had collected over a thousand deadly poisons, each extremely potent.
December 20th.
Ryuji collected over two thousand different deadly poisons, but the poison produced within Kana's body had started repeating.
December 24th.
Kana's body could no longer produce new poisons.
For safety, Ryuji conducted tests for two more days. Confirming no issues, he began data organization and preparations to implement the solution.