Even in the Naruto world, where forbidden techniques were everywhere and senjutsu seemed to grow on trees, the Summoning Technique still held a firm place among the highest tiers of ninjutsu.
Its essence was not especially difficult to understand. It could be regarded as an alternative form of Space–Time Ninjutsu. First, a contract was established between the summoner and the summoned party. Then, in battle, the Summoning Technique could call that contracted party from virtually any location directly to the summoner's side to assist in combat.
This could be divided into Blood Summoning and Non-Blood Summoning. The former was generally used to summon living creatures, while the latter was usually used for inanimate objects.
Because the technique's operating principle allowed a user with sufficient chakra to call previously prepared objects or allies to their side at any time, this convenient ninjutsu was favored by nearly every powerful shinobi.
Naturally, the contract worked both ways. If the summoned creature could perform the Summoning Technique, it could likewise summon its own contractor.
"Then adding a Summoning Contract like this should make things much more convenient."
Hinata looked with satisfaction at the Summoning Contract in her hands. It was simple, essentially a contract between two individuals. She cut her finger with a Kunai and pressed a bloody print of her right hand onto one side. Then she cut Suigintou's finger, took that hand, and pressed another bloody print onto the other side.
With that, a mutual Summoning Contract had been established between Hinata's body and Suigintou's body.
This Summoning Technique also differed from the ordinary version in one particular way.
To be precise, it was called the Kagemusha Technique. The principle was easy to understand: a modified Summoning Technique that used a special contract to force the summoned creature to obey the summoner's commands.
Ordinary summoned creatures might obey their master's instructions, but they could never achieve the absolute coordination of two bodies sharing one mind. This forbidden technique therefore temporarily suppressed the summoned party's consciousness, making them obey the summoner completely like a puppet.
Given that, it was hardly surprising where the Kagemusha Technique came from. Naturally, it was found in the Scroll of Seals, courtesy of Senju Tobirama (Second Hokage), the man who contributed the most techniques and took the blame for the most problems.
Hinata carefully put away the scroll containing the Summoning Contract, then looked with satisfaction at Suigintou's body lying roughly three meters away. She quickly smeared the blood from her finger and formed the necessary hand seals. The Summoning Technique completed, smoke burst outward with a bang, and Suigintou's body vanished from three meters away before reappearing beside Hinata.
More importantly, Hinata could clearly feel that the Suigintou body before her could now be controlled directly. There was no doubt about it. The added alterations to the Summoning Contract had successfully created the Kagemusha Technique.
"Very good~ Secret Technique! Demonic Mirroring Ice Crystals!"
Imagining the steps of performing Demonic Mirroring Ice Crystals while controlling Suigintou, Hinata immediately sensed chakra moving inside the body before her. Suigintou's eyes were open, but her gaze remained dull and puppet-like as she smoothly raised one arm. The air around her rapidly condensed, forming several hard, gleaming Ice Mirrors.
"How convenient. As expected of the Second Hokage. It's such a shame no one uses a useful technique like this."
Hinata gave a thoroughly wicked laugh and casually released the summoning state. Suigintou's body returned to the place where it had originally been lying, and the sensation of their consciousnesses being linked disappeared with it.
All right. There was, in fact, a perfectly good reason no one used this technique of the Second Hokage.
The technique had been designed for living summoned creatures. The original purpose of summoning was for a user to request help from the being they had contracted. Those summoned beings could also perform a reverse summoning on the user, allowing both sides to draw on each other's strength when necessary.
At its core, then, the Summoning Technique was a contractual ninjutsu built around 'fairness' and 'equality.'
The Second Hokage's Kagemusha Technique, however, had slyly tampered with that contract. It amounted to forcibly enslaving the summoned creature, making it no different from a crooked merchant secretly altering a business contract for one-sided profit. No wonder the technique could never be taken into general use.
After all, it did not work on inanimate objects, and summoned creatures were not fools. If someone used this black-hearted version of summoning on another living being, the user's reputation would probably become infamous throughout the entire summoning world. Intelligent summons were hardly less clever than humans, and they had information networks of their own.
In other words, only someone willing to give up on ever contracting other summoned beasts—and even accept being hated by all of them—could afford to use this Summoning Contract without restraint.
Naturally, it made perfect sense that the technique had gone straight onto a forgotten shelf in the Scroll of Seals as soon as it was developed.
What? You could use it to enslave people too? True, but that introduced another problem. Someone loyal to you would help without a coercive technique in the first place. Someone disloyal might be bound temporarily, but the moment the Kagemusha Technique ended, the controlled person would recover their own will.
And... the most awkward part was...
The damned contract still worked both ways...
Even though the Second Hokage had strengthened it so the summoned party was forced to obey the summoner, he still could not bypass the most fundamental rule of the Summoning Contract. It was like a crooked merchant's predatory contract still needing, at least on paper, to claim mutual benefit. Which meant...
You could summon someone, force them through a full set of radio calisthenics, and then, the moment the technique ended, they could furiously reverse-summon you and force you through an entire yoga routine. It was a perfect ninjutsu for mutually assured humiliation.
Unless you intended to summon the target once and immediately force them to commit suicide, ending the technique would basically mean sitting around and waiting for revenge. And if killing an enemy was the goal, going to all that trouble was less efficient than simply cutting them down.
The Second Hokage must have felt fairly awkward after developing it. It could not be used on summoned beasts without consequences, and using it on humans led to mutual retaliation. So he simply put it into the Scroll of Seals, where it remained until Hinata dug it out recently.
However, the medical knowledge of the Second Hokage's era apparently had not included the concept of a 'vegetative state.' Because of that, he had missed the most important edge case: what happened if the summoned person's body remained alive, but all independent consciousness and thought had already been lost?
In that condition, the brain could still receive commands from the summoner, allowing the body to carry out instructions perfectly while summoned. Once the summoning ended, the summoned party would simply return quietly to wherever their vegetative body had originally been placed.
After carefully studying the technique, Hinata was delighted. The Second Hokage had left her quite a useful legacy, one that conveniently allowed her to establish a direct link with her backup body.
"This is fantastic. Even if the Hyuga Clan body is somewhat lacking in combat power, it doesn't matter. As long as I can summon Suigintou's Sage Body whenever I need it, my early-stage self-defense problem is basically solved."
Hinata emerged from the basement in high spirits, stretched happily in the light coming through the window, then casually tossed the summoning scroll at her waist into a drawer. The scroll only contained the contract between Hinata and Suigintou, so it did not matter even if someone else obtained it. At worst, destroying the scroll would break the contract between the two bodies.
Hinata had spent about twelve hours completing the initial arrangements in the Land of Waves. From then on, she only needed to appear periodically. She could even have Konan use the Transformation Technique to fool the craftsmen if necessary. After all, Pain's position also had to be taken into consideration. When another person yielded ground to you, it was not only a sign of respect or calculation; it was also an implicit test of your attitude.
The best response was therefore to return that concession at the right time. Give and take was what kept cooperation running smoothly. If only one side kept advancing while the other did nothing but yield, the relationship stopped being cooperation and became invasion.
Especially when one's partner was a nuclear-warhead-class shinobi like Pain, who might answer a disagreement with Shinra Tensei, restraint and caution were advisable.
So after arranging the factory construction, Hinata simply returned to Konohagakure and left the remaining work to Konan. From then on, she only needed to observe the development of the Land of Waves at regular intervals.
Even if the Figure factory in the Land of Waves never paid her a single share of the profits, she had already gained plenty. At the very least, it guaranteed a stable supply of Fox's Tale Figures. It was like constructing a prerequisite building in a management game.
This time, she had been cautious enough to install a Camera in the room where her original body was kept. She wanted to see clearly whether the body would move on its own after her soul left it.
But the Camera footage put her at ease. During the twelve hours her soul had been away, the body showed no sign of autonomous activity whatsoever. It was exactly like a person in a true vegetative state.
So the previous incidents had only been coincidences?
After thinking for a while, Hinata ultimately decided not to dwell on it. There were already enough strange things in this world. Saving herself the mental effort was probably wiser.
In any case, as long as she was the one using this body, then~ the existence known as Hyuga Hinata would continue in exactly the form she desired.