The two of them seemed to have completely forgotten what had just happened.
Tanaka did not ask why Tsunade was feeling down, nor did he question why she greeted him with a direct face attack.
Tsunade also didn't offer any explanation, nor did she apologize for her Cleansing Face Technique and her aggressive close-contact move on him.
Just like that.
The two of them took turns eating, bite by bite, finishing off the strawberry and succulent grapes in their hands before Tsunade finally steered the conversation back to the main topic.
"Tell me. What method do you plan to use to train the Eight Gates?"
Tsunade put down her empty cup.
For someone like Tanaka, who had broken the Caged Bird and developed a technique surpassing the Flying Thunder God, she dared not underestimate him in the slightest.
"If there were a technique that could temporarily strengthen the entire chakra pathway system, making it as tough as iron, would it be able to mitigate the side effects of the Eight Gates?"
Tanaka spoke each word carefully.
That was right.
The technique he was referring to was actually Armament Haki.
The advanced application of Armament Haki allowed it to be projected outward and penetrate the surface of objects, directly damaging them from the inside. This was the same technique Rayleigh demonstrated to Luffy during his training.
Whether it was other materials or human bodies, it could "pass" through them.
Since Haki represents the manifestation of willpower rather than a physical substance, its application should theoretically be limited only by one's control and perception.
Just as chakra could be directed to specific parts of the body through precise control, he theorized that Haki could be similarly focused inward with sufficient mastery. The key difference was that while chakra pathways were well-documented and traditionally manipulated, directing Haki to internal organs required a level of bodily awareness most users lacked
This could explain a limitation he had observed in even the most powerful Haki users.
Despite their mastery, Admirals and Yonko alike seemed to apply Armament Haki only externally—coating limbs, weapons, or their entire bodies. None appeared capable of selectively hardening internal organs like their hearts or lungs.
Tanaka suspected this wasn't a limitation of Haki itself, but rather of the user's perception. Without a way to precisely visualize their internal structures, even legendary pirates and Marines lacked the sensory awareness needed for such fine internal control.
In other words, Haki users themselves couldn't see inside their own bodies. They couldn't directly observe their blood vessels, bones, or organs, so of course, they couldn't precisely channel Haki into a specific organ and then harden it.
By comparison, flowing Haki outside the body, wrapping it around the skin and muscles, then hardening it, was far easier.
However, the issue of "not being able to see inside the body" was not a problem for Tanaka at all.
The Byakugan could see through everything—not just as simple X-ray vision but at a microscopic level. Forget just organs and bones; the Byakugan can even perceive the chakra pathway system, which was far more delicate than blood vessels, as well as acupoints.
And it did so with a full 360-degree field of view.
With the Byakugan's vision and insight, he could precisely channel Armament Haki into the chakra pathway system and apply the hardening effect before activating the Eight Gates.
If that still wasn't enough, there was also the Op-Op Fruit, which allowed him to directly manipulate anything within his ROOM.
Including Haki.
This was his plan.
And currently, it was the only method that could minimize or even eliminate the damage the Eight Gates inflicted on the body.
"You don't think the Eight Gates only damage the pressure points, do you? That the harm only comes from opening the gates?"
"The damage from opening the gates aside, the toll that combat takes on the body is another major burden."
"The defining characteristic of the Eight Gates is being faster and stronger."
"The speed and punching force that surpass the speed of sound, the fists that shatter mountains, and the kicks that split rivers—these put extreme strain on the muscles, bones, joints, organs, blood vessels, and chakra pathway alike."
"To put it simply, the damage your body sustains from fighting with the Eight Gates is even greater than the damage caused by just opening the gates."
Tsunade shook her head.
"I won't ask you yet how much your technique can strengthen the chakra pathway—I'll just ask you one thing."
"Skin, muscles, bones, joints, organs, nerves, blood vessels, and chakra pathway."
"Can your technique simultaneously cover all these systems and make them as tough as iron?"
As a master of medical ninjutsu, she pinpointed the dangers of the Eight Gates with just a few words, as well as the difficulty and feasibility of eliminating or mitigating these risks.
"It should be possible."
Tanaka thought for a moment and then nodded.
"Is that so?"
"If you can really do that, then we still need to determine the exact level of reinforcement your technique provides."
"Can it withstand the Gate of Opening? The Gate of Rest? The Gate of Life? Or even the later gates?"
"Until we figure that out, you are not allowed to train in the Eight Gates on your own."
Tsunade gave Tanaka a deep look.
A genius who could develop a space-time ninjutsu—he was indeed extraordinary.
As far as she knew, the Hyūga clan had no technique that could enhance the body to such an extent.
In other words, if Tanaka really possessed such a technique, then it meant he had developed it himself.
"Don't worry, Lady Tsunade. I'm actually very cautious with my life."
"Besides, with a top-tier medical-nin like you agreeing to be my personal doctor, how could I possibly train the Eight Gates recklessly on my own?"
Seeing Tsunade's serious expression, Tanaka quickly reassured her.
He wasn't that reckless.
With Tsunade by his side, why would he train the Eight Gates blindly on his own?
In the vast shinobi world, only Guy and his father had successfully trained in the Eight Gates without crippling themselves.
"It better be that way."
Hearing his repeated assurances, Tsunade finally felt at ease. She then glanced at the two empty cups in front of her.
She decided to consider them as payment for the grape and strawberry drinks.
That was what she told herself.
"Alright, continue your training. I should get back to teaching your clan members medical ninjutsu."
After confirming that Tanaka wouldn't secretly train the Eight Gates, she stood up to leave. But just as she turned around, she seemed to remember something. Reaching into her pocket, she pulled out a scroll and tossed it behind her toward Tanaka.
"Take this. If you don't understand something… Come ask me again."
Although she said that, she still turned back around.
"Activate your Byakugan."
She looked at Tanaka and suddenly said something shocking.
Tanaka was slightly surprised and hesitated.
Because in the ninja world, there was an unspoken rule—If a Hyūga clan member used the Byakugan on a kunoichi without permission, it was essentially a declaration of war.
Let alone the fact that this kunoichi was Tsunade.
"What are you thinking? Did I ask you to see through my clothes?"
"I'm asking you to look at my body's chakra pathway system and chakra flow."
Tsunade said impatiently.
Although she was still unmarried and single, she was a veteran of the Second Great Ninja War and one of the Sannin. As a medical-nin, she wouldn't blush or get embarrassed over something like this.
"The fact that the Byakugan has x-ray vision is well-known in the shinobi world. Logically, the Hyūga clan shouldn't be able to make any friends in the village."
"But in reality, whether male or female, many ninjas are willing to befriend Hyūga clan members."
"Do you know why?"
Tsunade gave Tanaka a teasing smile.
"Why?"
Tanaka genuinely didn't know.
His knowledge of the Byakugan was limited to combat, training, and scouting.
He had never thought about using it for peeping.
"You really don't know?"
"Not bad."
Seeing that Tanaka wasn't pretending, Tsunade was even more satisfied with the young ninja before her.
She pointed at her "chest weapon," which she used for her bloodline limit techniques, then casually dropped an earth-shattering statement.
"Alright, activate your Byakugan. But don't look at my body—just see through my clothes."