Chapter 22 – Monstrous Strength
The meal took about half an hour. Uzumaki Mito still upheld the old rule of "Do not speak while eating, do not speak while sleeping." Not a single word was exchanged at the table, which made things much easier for Ren—he didn't have to force himself to make small talk.
Truth be told, Ren had always been curious about how exactly the Senju clan met its end. The original work never mentioned it at all. It was only in the past two days, while browsing through ANBU archives, that he started piecing together some clues.
From what he could gather, the primary responsibility lay with the Second Hokage, Senju Tobirama, and the secondary blame with Danzō.
The reasoning was simple. During Tobirama's tenure as Hokage, the village was almost constantly at war. Wars needed shinobi. Tobirama didn't trust the Uchiha, so he preferred to take members of his own clan into battle, while Uchiha shinobi were assigned to different fronts.
This created a problem—Uchiha, with their Sharingan, grew stronger the more they fought, but the Senju clan gained little benefit from constant warfare. Add to that the fact that the intensity of the Shinobi World Wars far surpassed the earlier clan skirmishes, and the Senju population soon fell below the survival threshold. By the time Tobirama realized the danger, he was already killed by the Gold and Silver Brothers(Kinkaku and Ginkaku).
That also explained why there were no official records on the Senju's downfall—it was essentially the leader's own blunder. The Third Hokage, out of respect, chose not to document this embarrassing episode.
As for Danzō's role, there wasn't much to say. The Senju population was already dwindling, and then he decided to carry out his "research." After a few such experiments, the rare and precious "specimens" of the Senju were almost completely wiped out, leaving only Tsunade and Nawaki as the symbolic remnants of the clan. It was a dirty move, and Hiruzen knew it—hence his efforts to go above and beyond in making it up to Tsunade.
All of this was Ren's deduction from the ANBU scrolls—not 100% certain, but likely close to the truth. Otherwise, how else could one explain why Tsunade never made a fuss, or why Mito never sought revenge on those who destroyed her clan?
Tsunade, noticing Ren drifting off into thought, waved her hand in front of his face.
"Are you even listening? I just told you the prerequisites for Chakra Enhanced Strength. Did you understand?"
"No, Sensei. Could you repeat it? I was just thinking about something in ANBU."
"Fine, I'll say it again. The foundation of Chakra Enhanced Strength is twofold—an enormous amount of chakra, and chakra control so precise it borders on perfection. Lacking either will injure your own body during training." Her fair, delicate face was utterly serious.
"And when you say 'enormous,' how much chakra are we talking about? Can it be measured?" Ren asked.
Tsunade nodded. "Orochimaru once gave me a ninja tool. Pour chakra into it, and it pushes up a water column. A typical jōnin can raise it to about twenty centimeters. If you want to learn Chakra Enhanced Strength, you'll need to hit one meter."
Ren fell silent. He wasn't sure—could his chakra reserves push it that high?
Tsunade led him to the device. Placing his hand on it, Ren released chakra with all his might.
Ten centimeters… twenty… thirty… the water column finally stopped at half a meter.
"That's not enough," Tsunade said, shaking her head. "Without sufficient chakra reserves, you simply can't unleash Chakra Enhanced Strength. Still, for your age, your chakra levels are already far beyond your peers. Perhaps in two more years, you'll be ready."
"Then… can I at least start with chakra control?" Ren asked cautiously.
"You can. The best way to train chakra control is through medical ninjutsu. In that sense, you were smart to choose me as your teacher—Jiraiya and Orochimaru's chakra control is rough and inefficient." There was a trace of pride in her voice.
Ren fully agreed with that. Tsunade's grasp of chakra control was unmatched. Even in the later days of the Fourth Shinobi War, when Kage-level battles raged, Naruto could drain himself dry just by overusing the Rasengan, while Tsunade almost never had to stop mid-battle to recover her chakra.
From her portrayal in the original work, Tsunade was without a doubt one of the most chakra-demanding shinobi in the entire ninja world.
With Katsuyu, she could heal injuries; with the Yin Seal, she could store massive amounts of chakra; with the Strength of a Hundred Seal, she could draw upon that chakra freely to boost her speed and striking power; and with Creation Rebirth, she could instantly restore herself to peak condition.
Faced with that relentless barrage, even the rogue sannin Orochimaru was left dumbfounded.
Tsunade could press the attack without her chakra ever dipping into the red.
That was Tsunade.
"Sensei, what's the principle behind Chakra Enhanced Strength?" Minamoto Ren asked, deeply curious about this A-rank technique. The difficulty and sheer power it promised were clear just from its reputation.
Tsunade didn't answer with words. Instead, she rose to her feet and walked toward the training grounds of the Senju compound.
Ren quickly followed.
They stopped. Tsunade turned sideways toward him, raising her right fist in his direction.
"Watch closely, and tell me what you see afterward," she instructed.
"Chakra Enhanced Strength!"
Her seemingly delicate fist slammed into the ground. In an instant, the earth cracked apart, fissures racing toward Ren's feet. He could actually feel the ground tremble.
When the dust settled, Tsunade withdrew her fist and looked at him. "Did you see it clearly?"
Ren frowned. "Your fist… didn't actually touch the ground, but the earth still split."
Tsunade clapped her hands—smack!—and grinned. "Exactly!"
Ren's eyes widened. He was starting to understand.
Tsunade didn't let him dwell in uncertainty. Pointing to the cracked earth, she explained,
"Chakra Enhanced Strength isn't about the strength—it's about the monstrous part."
"It's actually a chakra-based, non-elemental technique. If you added any elemental nature change, you'd destroy your own hand."
"To use it, you need to channel chakra to the surface of your fist and release it in rapid, repeated bursts—like the back-and-forth sprints at the academy. In theory, you could repeat these short bursts infinitely, but in practice, hitting a hundred times per second is already exceptional."
Ren now fully understood—it was like strapping a pile driver to his fist. The repeated chakra impacts delivered far greater destructive force than raw physical strength ever could.
No wonder Tsunade could smash stone and earth without her pale, smooth hands ever suffering damage—her chakra was doing the striking for her.
Seeing his realization, Tsunade laughed with her hands on her hips.
"Don't be fooled by how simple the principle sounds. Meeting the conditions to actually use it is incredibly strict. Jiraiya and Orochimaru both tried, but they don't have the same chakra reserves I do. Even getting those 'chakra drills' to breach the skin surface was hard for them—not to mention their pitiful chakra control."
Ren clicked his tongue. No wonder this was an A-rank jutsu—the difficulty lay entirely in its prerequisites.
"So, still want to learn it? Or should we pick something else?" Tsunade asked. She knew this technique might be too demanding for him, and mastering it would take a long time.
"Learn it! Of course I'll learn it!" Ren said firmly. He refused to believe he couldn't master this jutsu. The ninja world was full of difficult, complex techniques—but Chakra Enhanced Strength was vital for his growth.
Without it, his kenjutsu would hit a ceiling at the Kage level.
With it, he could take a blade… and cut down Uchiha Madara himself.