Tsunade Senju was the undisputed "Princess" of Konoha.
Not only was she one of the legendary Sannin, but she was also the beloved granddaughter of the First Hokage, the "God of Shinobi," Hashirama Senju.
Compared to her invincible husband, Hashirama's wife, Mito Uzumaki, was not as famous.
Even among the Konoha ninja who had met her in person, the impression of Mito Uzumaki was merely that of "a very kind and amiable old lady who loved the village and supported and protected all those she loved."
But as her granddaughter, Tsunade still remembered the immense power of sealing jutsu.
How strong was sealing jutsu? Few in the current shinobi world could say for sure. After all, this complex and profound system had declined.
Not many people remembered that Mito Uzumaki's mastery of sealing jutsu had reached the level where she could suppress and seal the full-fledged Nine-Tailed Fox. Although she couldn't communicate with it telepathically, she could control the Nine-Tails' chakra with ease. After Hashirama's death, for a long time, she was the de facto strongest combatant in Konoha!
Back then, the Uzumaki Clan, who had a close relationship with the Senju Clan for generations, relied on their powerful sealing jutsu to stand tall in the world. But it was precisely because of this that they were envied and coveted by many countries and ninja clans. After a tragic event that silenced the entire shinobi world, the Land of Whirlpools was destroyed, and the Uzumaki Clan scattered, becoming a name in history.
Since then, sealing jutsu had declined, and the truly world-altering grand sealing jutsu were lost one after another.
But Tsunade Senju knew that the village held many treasured, solitary copies of sealing jutsu.
—Back then, her grandmother's journey from afar to marry her grandfather was a super marriage that shook the entire shinobi world. The dowry she brought was considerable, including a wealth of knowledge on sealing jutsu.
Dead Demon Consuming Seal, Four Symbols Seal, Yin Seal... Certain powerful sealing jutsu were in the hands of Konoha ninja.
However, although sealing jutsu was powerful, the threshold for learning it was high. Similar to Space-Time Ninjutsu, it was a field exclusive to geniuses. For ordinary people, studying sealing jutsu was truly less practical than learning a few Fire Release techniques.
Tsunade rubbed the purple, diamond-shaped mark on her forehead and beckoned Hyuga Yuto.
"Yuto, come here."
"What is it, Sensei?" The Branch House boy stood before the blonde woman. He was still using Mystical Palm Technique to heal his arm, but fortunately, the bleeding had stopped, and it was bandaged. Tsunade wouldn't have a relapse of her hemophobia.
"Yuto," Tsunade tapped his forehead protector.
"There's a jutsu I want you to try... Do you know about this mark on my forehead?"
"Yes, I do. You told me about it." Hyuga Yuto nodded.
"Yin Seal."
"Now, I want to teach you this jutsu." Tsunade paused, organizing her words.
"Yin Seal, an S-rank supplementary ninjutsu. Its function is to gather, regulate, and control chakra. After achieving a small degree of mastery, a diamond-shaped mark will appear on the forehead. Further mastery allows the user to maintain their youth and beauty through the Yin Seal's low output and fine-tuning."
"My grandmother, Mito Uzumaki, also had this mark on her forehead."
"However, my [Yin Seal] is different from the ordinary Yin Seal. I've made many improvements and developed extended techniques based on them. It's quite different from the original version."
"I named this mark... the Strength of a Hundred Seal."
"The Yin Seal requires meticulous effort. Patience is key. Practitioners must spend a lot of time regulating and accumulating their chakra to condense this Strength of a Hundred Seal."
"Don't be impatient, Yuto. Take it slow. Starting this afternoon, you'll try to learn the Yin Seal. Of course, don't neglect your medical ninjutsu and Super Strength training."
Hyuga Yuto nodded solemnly.
"Sensei, I won't disappoint you!"
"Mm." Tsunade ruffled the Branch House boy's hair with a grin.
"Do your best."
Hyuga Yuto asked a few more questions about the precautions for practicing the Yin Seal, then went to the side to continue healing his injuries.
Tsunade sat on the ground, hugging her knees, and gazed at her talented disciple with a complex expression.
To prevent her student from feeling too much pressure, she didn't tell Hyuga Yuto a few things.
In fact, the main purpose of teaching the Yin Seal was to test Hyuga Yuto's talent for sealing jutsu!
Anyone could learn the Yin Seal with enough time and effort. It was just a matter of how long it took. Most practitioners would succeed in their fifth year.
But succeeding in the fifth year meant having no particular talent for sealing jutsu, just average aptitude.
Succeeding in the third year indicated a small amount of talent.
Completing the jutsu in the second year meant being a genius, suitable for learning sealing jutsu.
Succeeding in one year was a feat rarely achieved even in the Uzumaki Clan's heyday. This signified true talent, a precious gem that, with careful polishing, could steadily become a top-tier Jonin or even a Kage-level master. Mito Uzumaki was one such example.
The Yin Seal was, in a sense, a "sealing jutsu talent detector"!
Tsunade's thoughts were clear:
If Yuto's progress was rapid and he displayed a good aptitude for sealing jutsu, she would continue to teach him sealing jutsu knowledge and research the extremely difficult method of temporarily sealing "damage."
If Yuto didn't have this talent, she would find another way. At worst, she would use the most basic method—since Lion's Fang Bite Sever would damage the user's body, she would simply use Ninja Art: Creation Rebirth to withstand the damage. You destroy, I heal. It was a bit crude, but it was a workable solution.
In fact, given Tsunade's personality, she preferred the second option. It was straightforward, and she had the HP to spare.
But she understood that her disciple was a Hyuga, not a Senju known for their vitality and abundant chakra. He definitely wasn't as resilient as she was and probably couldn't withstand the repeated process of destruction and healing.
"Eh? Wait, I think I forgot something important..."
The blonde beauty suddenly scratched her hair, realizing something.
She abruptly looked up at Hyuga Yuto.
In the forest, no more than twenty meters away from her, the handsome young man was stroking his arm, carefully healing himself. His face was handsome and fair, his figure well-proportioned and slender. He looked like a young master who had never done any manual labor. But upon closer inspection, one could see the thick calluses and scars on his palms, evidence of the countless arduous training sessions and battles he had endured.
Tsunade opened her mouth, but in the end, she didn't say anything.
She slumped to the ground, muttering in a self-defeating manner,
"Forget it, forget it. If anything goes wrong, the old man will take the blame for me anyway... Yes, I'll go talk to the old man later."
...
That evening, at the Hokage Tower.
Hiruzen Sarutobi looked at his female disciple standing obediently before him, incredulous.
"Tsunade... You want to teach Hyuga Yuto... No, that's not the right way to put it." He paused, his tone becoming serious.
"You plan to teach the high-level sealing jutsu of the Uzumaki Clan to a child from the Hyuga Branch House?"