"So women are emotional, especially girls your age who aren't adults yet." Looking at the girl who seemed moved to the point of tears, Ryuji said indifferently, "While researching Hawk Eyes, I gave you a physical examination. There's a tumor in your brain that others don't have."
'Huh!?'
Kana was stunned for a moment. Seeing Ryuji's expressionless face that didn't seem fake, she couldn't help but doubt: 'Could it be that I was overthinking things?'
"Since there are no other samples, I'm not sure if this tumor is a problem unique to you or something all Kagero Clan's members have. I also don't know if it's the key to producing the poison. But since there's the pattern that poison is produced only when desire is felt, there must be a principle that can be found and solved."
"It's not that easy."
When talking about serious matters, Kana also put aside her wild thoughts and said seriously, "Our clan's secret scrolls mention that every Kagero Clan's woman has such a tumor in her head that others don't have, and it is precisely the culprit of our special constitution."
"There are related records?" Ryuji was taken aback in surprise, then said nonchalantly, "That's even better. It saves time for confirming research. Let's just remove it."
"If it were that simple to solve, we wouldn't have lived in seclusion in the deep mountains." The girl said gloomily, "For hundreds of years, our clan has wanted to solve this problem every moment. Many predecessors who were very skilled in human body research have emerged, but all ultimately failed. Whether it's removal, Medical Ninjutsu, or even medicinal herbs… nothing works. Once the tumor is altered, the host quickly dies."
"That stubborn?"
Ryuji frowned.
Although times develop and people progress, this doesn't hold true for the Shinobi World. Because the origin of Ninjutsu is the descent of aliens. They were born with technology far surpassing the modern era. Even though much technology was lost during inheritance, people today don't necessarily dare to say their technology is more advanced than the ancients'.
For the entire Kagero Clan to spend hundreds of years without solving the problem… this is indeed a difficulty beyond imagination.
But...
"What others can't do doesn't mean I can't. Today, let me show you my ability, Senki Ryuji's skill."
"This is not something that…"
Her words were cut off halfway. Kana looked in astonishment at the spatial portal opening behind Ryuji, confirming, "You're really going to spend time researching the Kagero Clan's physical problem?"
Because she needed to cooperate with Ryuji's Hawk Eye research, Kana had been to Ryuji's Personal Space. She knew that was his laboratory and that he had many other things to do.
During the time she assisted his research, she hardly ever saw Ryuji rest. Even while conducting one experiment, he would often use the waiting intervals to work on other experiments.
'I've already told him the difficulty of the problem. He is clearly so short on time. Why is he still willing to help someone like me who has no relation to him, even was once an enemy? Do I truly possess such value for him to do this?'
"Come in quickly."
The man's urging snapped Kana out of her thoughts. She looked up to see Ryuji waiting for her from within the spatial portal.
"Coming."
Kana hurriedly ran towards the spatial portal.
Regardless of the reason, her mission was to solve the extinction crisis of the Kagero Clan. If an opportunity existed, she would take it. The other party was the one who created the Mechanical City. She had witnessed over five thousand square kilometers of land take flight. Perhaps, the other party truly could create a miracle and completely solve the Kagero Clan's special constitution problem.
…
Entering the spatial portal, arriving in the familiar laboratory,
Kana followed Ryuji to the platform where her body was initially examined.
"Lie down."
Ryuji said to the girl.
Kana glanced at the floating crystal ball on the platform and couldn't help but hug her chest, her two large headlights squeezed to appear even more magnificent.
Ryuji frowned, displeased. "Don't make unnecessary movements. Even if I can control my desires, suppressing them is very uncomfortable. Don't you have any awareness of your own seductive body?"
Kana also realized her action was inappropriate and immediately put her hands down, her face blushing as she said, "Last time during the checkup, didn't you say you had backed up my data and didn't need to check again?"
"Last time was only to examine your body structure. I didn't specifically observe the operational state of that tumor."
"Oh, oh."
Kana nodded, then prepared to lie down.
But just as she sat on the platform, she froze.
She suddenly remembered a problem.
That was, for the tumor to start operating and the body to erupt with poison, one must first fall into the throes of desire.
'Is this guy using the pretext of helping research the problem to try to do something to me?'
Thinking this in her heart, she saw Ryuji take out a kunai, holding it by the blade end and handing it over handle-first.
"What... what does this mean?" Kana didn't quite react.
"I don't have a suitable rod here. You'll have to make do with this!"
"Huh?"
'Make do with this?'
'Make do with what?!'
The girl, confused, took the kunai and was about to ask when she heard Ryuji ask again, "First, confirm something. Your bodily fluids won't turn into corrosive poison, right?"
"???"
Kana blinked.
She looked at the young man who was putting on a gas mask and finally understood what he meant by 'make do'.
Instantly, her face turned bright red.
"You... you want me to do that kind of thing in front of you?"
"If you have other ways to produce desire, you don't have to do it."
"But, but..."
"Hmm!"
Ryuji pointed at the female corpse preserved in a jar opposite. It was very intact, the skin showed no discoloration at all… it didn't look dead at all.
"Don't overthink it in front of a medical professional. I've seen and touched more naked bodies of women more beautiful and with better figures than you. I've even handled all the organs inside their bellies and heads."
"..."
Kana withdrew her gaze, looking speechlessly at Ryuji.
Sometimes she felt this guy was really gentle, but other times she felt he was like a fool. And sometimes she felt everything about him was an act, his real goal just to piss people off without letting the angered party find a reason to refute.
'And what does he mean 'women more beautiful, with better figures than me'?'
'Are there women in this world more beautiful and with better figures than me?'
'Hmph!'
Kana huffed and lay down on the platform. After hesitating for a moment, she turned her head to look at Ryuji.
"Wait a moment!"
Hearing the voice, Kana turned her head in confusion.
"You haven't answered yet. Does your poison possess corrosive properties? I don't want to be taken out by the problem while trying to solve it."
"..."
Kana was speechless.
She had finally put aside her shame, only for this jerk's words to bring it back.
'Doing that kind of thing in front of a man… does he really think I'm a wanton woman?'
However,
This was a matter related to safety, so Kana didn't dare be careless and replied truthfully, "I'm not sure either."
"Not sure?"
Ryuji turned his head, looking at her in astonishment. "Why wouldn't you be sure?"
"The poison we produce each time is different." Kana explained, "Depending on the degree of desire and the cause of the desire, the poison produced in our bodies also differs. I personally haven't produced corrosive poison, but there are many such cases in our clan's history."
"A poison that mutates according to the situation... No wonder it's called an incurable lethal poison." Ryuji's expression turned serious.
Only with some knowledge in this area would one know how tricky a poison that mutates according to the situation is.
To put it this way, no matter how much Jiraiya's novel emphasized how terrifying this poison was, and no matter how much Kana emphasized how difficult their constitution was to solve, none made him feel as challenging as this piece of information.
"So, are we still checking?" Kana asked timidly, sneaking a peek at Ryuji.
Although doing that kind of thing in front of a man made her wish she could crawl into a crack in the ground,
But compared to solving a problem that had plagued the Kagero Clan for hundreds of years, even bringing the clan to the brink of extinction, it was hardly a problem at all.
"Check, why not check?" Ryuji came back to his senses, looking at the girl seriously. "As long as this poison follows a pattern, there must be a way to solve it."
"Alright."
In the face of major matters, Kana also stopped caring about shame.
As time passed, the girl's breathing gradually became rapid, her face also gradually flushed.
Under the effect of her seductive body, the breath the girl exhaled turned into pink mist, eroding all life.
Fortunately, after hearing that the Kagero Clan's poison might possess corrosive properties, Ryuji had already put on protective gear and was unaffected.
He activated the Observation Device.
Following Ryuji's instructions, the crystal ball projected a scanning light. A virtual simulation of Kana's body structure was projected, and it was a real-time broadcast.
In the projected image, the tumor in Kana's brain pulsed and contracted with her breathing, then emitted a subtle energy through the central nervous system to various parts of the body.
"This is… Spiritual Energy!?"
Ryuji enlarged the image of the tumor area, carefully observing its operating principle.
"Wrong, it's not Spiritual Energy."
"So that's how it is!"
Through observation, Ryuji understood the operating principle of the Kagero Clan's special constitution.
Most of the human body's actions are performed by the brain transmitting signals through the central nervous system.
This tumor is located on the main pathway where the brain's central nervous system transmits signals to the body. Therefore, it and the host's body mutually influence each other.
When the host feels desire, this tumor starts working, emitting a certain substance around it.
This substance poses no harm to the host, but it gets carried away by the Spiritual Energy flowing from the brain to the body, further combining with Physical Energy to refine Chakra.
As is well known, Chakra is life energy.
Chakra contaminated by this special substance in turn affects the body, making the host more seductive, and also turning bodily fluids into poison.
'Is this a Kekkei Genkai?'
Thinking of the operating principle of the Sharingan, Ryuji couldn't help but shout, "Increase the intensity. Let me see what changes occur in the tumor with different degrees of desire."