Chapter 162: The Problem with the Yin Seal
The moment she felt the scorching heat in her abdomen, Tsunade's expression changed instantly.
It hadn't been long since she had just escaped from Hikari's Tsukuyomi illusion, and this sensation immediately made her recall certain experiences from within that illusion.
As has been said before, Tsunade didn't actually go through any truly perverted or concrete ordeals in the Tsukuyomi dream.
So why did she have this reaction now? Why would leaving just a little later have made it too late?
There is a psychological experiment known as "Pavlov's dog."
Every time before food is given to the dog, a bell is rung or a red light is turned on. Over time, even without food, as long as the bell rings or the red light comes on, the dog will start salivating.
For example, in some countries where bear disasters are rampant, a clever expert once suggested having students wear bells, believing that the sound would scare the bears away.
The result was that not only did the bells fail to scare the bears, but every time the bells rang, the bears thought it was mealtime and came running over to eat people.
This kind of situation is a conditioned reflex at the psychological level, an automatic response that doesn't require conscious thought. As a result, even intelligent beings like humans find it hard to resist when facing it.
At its core, it is about linking two things that seem unrelated.
And Tsunade experienced exactly this kind of association in the illusion.
She had become Pavlov's dog.
What made it even more terrifying was that these two things were not actually unrelated.
Even though Tsunade, as a medical ninja, didn't have particularly deep expertise in psychology, she still grasped the issue through analogy.
That was why she felt a lingering fear afterward. She had almost developed a conditioned reflex called "the moment I think of you, I go oh-ho-ho-ho."
And now, as soon as she felt the burning sensation in her abdomen, those memories resurfaced.
But…
"Hm?"
Tsunade touched the sash of the bath towel tied around her waist and realized that the stone was gone.
She pulled the sash open, and sure enough, the stone hadn't fallen to the ground.
Had it fused into her body?
Before Tsunade could think any further, an even more intense sensation began to spread.
After activating the Strength of a Hundred Technique, her body was covered in black markings produced by the explosive increase in chakra when the Yin Seal was released.
These black markings were essentially chakra transport channels, rapidly and safely circulating the chakra stored in the Yin Seal throughout her entire body.
Now, however, the black markings on Tsunade's body began to turn golden, starting from her abdomen and spreading outward in all directions.
The natural energy contained within the stone Shiromo had given her seemed to be competing with the chakra stored in her Yin Seal for control.
As the golden markings drew closer to her head, where the Yin Seal was located, their spread gradually slowed. Meanwhile, her arms, which were farther away, were already completely covered.
During this process, Tsunade's body was continuously being torn apart and then reconstructed by Creation Rebirth, an agony beyond words.
Yet as one of the Three Legendary Sannin who had come from countless battlefields, Tsunade didn't make a single sound.
Watching the black markings on Tsunade's body gradually being swallowed by golden light, Shiromo felt as if he were watching Illidan Stormrage, the Child of Light and Shadow, being infused with holy light by the naaru.
It felt like Tsunade was about to shout, "My destiny is my own" and then throw a punch straight at him.
But nothing like that happened.
Before Shiromo arrived, there had never been anyone like Illidan in the entire ninja world, someone who was a chosen one, a savior, yet rejected that identity and believed that "we can only save ourselves."
Everyone was a slave to fate.
Even in the Boruto era, the so-called "information Jiraiya" Kashin Koji, who possessed the divine technique [Ten Directions](Prescience) and could see what was known as "all possible futures," was still nothing more than a slave to fate.
…
"Huh? Ah? Lady Tsunade, are you alright?"
Shizune had been staring closely at Tsunade's condition. When she suddenly noticed the abnormal changes in Tsunade's body, she cried out in alarm, her gaze turning toward Shiromo as if asking whether they could stop.
"I… I'm fine."
Tsunade continued to endure it.
She lowered her head and glanced at her hand, understanding why Shizune had cried out.
The skin on her hand had suddenly become wrinkled and shriveled, signs of aging.
Strangely enough, Tsunade didn't feel any sign of exhaustion. The pain hadn't lessened or faded, and her body still felt to be in peak condition.
Tsunade knew very well that if she nearly depleted the chakra in her Yin Seal, the youthful appearance she maintained with it would also disappear.
So why was this happening?
Was it because the chakra stored in the Yin Seal was gradually being devoured by the natural energy spreading out from Shiromo's stone?
As Tsunade pondered the reason, she had already moved to a corner, turned her back, and crouched down with her head lowered.
Clearly, Tsunade didn't want anyone to see her aged appearance.
At the moment, only her limbs were starting to show signs of aging. Soon, her body and face would most likely change as well.
Tsunade not wanting others to see her grow old was perfectly understandable.
Even the author, Kishimoto, didn't want the audience to see Tsunade grow old.
Shiromo, on the other hand, wasn't particularly curious about that.
Instead, Tsunade's current situation made Shiromo suddenly think of another issue.
"Tsunade, have you ever looked in a mirror and seen what you look like after aging?"
Shiromo asked.
"…No. Why?"
After a moment of silence, Tsunade answered while still crouching in the corner with her back turned.
In truth, it wasn't just that Tsunade had never seen what she looked like after aging. Rather, ever since she decided to use the Yin Seal to maintain a youthful appearance, she had never reverted back.
In the original story, Tsunade aged visibly twice: once during Pain's invasion, and once during the Five Kage versus Impure World Reincarnation Madara.
Both times, it was because she had exhausted her chakra while healing others.
If she didn't deplete her chakra, maintaining her appearance was essentially a passive ability for Tsunade.
Tsunade herself had also said that her youthfulness came from the inside out, not just a surface illusion.
In other words, her bodily state was also that of her youthful peak.
Under those circumstances, it was indeed hard to imagine why Tsunade would deliberately revert herself.
But because of that, a problem arose.
During Pain's invasion, it wasn't too bad. After Tsunade ran out of strength, that half-aged face looked about the same age as Jiraiya.
But in the battle against Uchiha Madara, that half of her face was downright terrifying.
You have to remember, Tsunade's real age was over fifty.
What does "over fifty" mean?
The resurrected Senju Hashirama and Senju Tobirama were roughly that age.
Now look again at Tsunade's face in the final stage of that battle with Uchiha Madara.
Are you sure that was fifty years old?
It looked even older than Sarutobi Hiruzen, who was nearly seventy.
If one had to find someone comparable in terms of age appearance, only ninety-year-old Ōnoki from the Boruto era showed a similar degree of aging.
The chakra in the Yin Seal could make the body younger. Logically speaking, even if the chakra were exhausted, at most she should simply return to her original state.
So how could she become even older?
This made Shiromo think of another, similar individual.
(End of this chapter)