"So it really was the Nine-Tails, huh…"
Hashirama looked genuinely troubled.
He honestly couldn't understand it.
In his mind, the Nine-Tails was dangerous, sure—but nothing that insane. To him, it was just: grab fox, smack fox, seal fox. Done.
The idea that a future Hokage died fighting it clearly didn't fit his worldview at all.
Still, he eventually let it go.
"Anyway," Hashirama said, scratching his cheek, "even if I have Wood Release… using it to ripen crops is impossible."
He waved a hand as if that should be obvious.
"If Wood Release worked like that, I'd have used it every day back when we first founded Konoha. The village wouldn't have relied so hard on Senju and Uchiha stockpiles just to get through the early years."
I felt the corner of my mouth twitch.
Yeah… I had suspected that would be the answer.
But if I didn't at least try summoning him and asking, it would've bothered me forever.
"Then, First Hokage-sama," I asked, eyes lighting up, "how did you develop Wood Release in the first place?"
If I couldn't use his jutsu directly to grow rice faster, then maybe I could extract a pattern from it.
Best case: I figure out the underlying principle and create a specialized plant-growth ninjutsu based on it.
"How?" Hashirama blinked. "I just… did."
I inhaled slowly.
Right. Of course. For him, it was about as complicated as "I breathed in, then I breathed out."
Orochimaru chuckled quietly at my expression.
Back in the day, the Third Hokage had described Hashirama to him as… "a terrifying monster with the personality of a child."
Now that he was seeing the man himself, it was very clear what Sarutobi meant.
"In that case, First Hokage-sama, could I ask you to come outside and demonstrate some of your Wood Release for me?" I tried again. "Just simple techniques are fine."
If I couldn't get "how-to", then at least I could get data.
Observe, measure, record, model—that was how science worked.
"Sure!" Hashirama agreed instantly.
We left the underground lab and entered a stretch of forest. There, Hashirama started casually tossing out Wood Release techniques—nothing too big, no "Deep Forest Emergence" or anything that would reshape the entire country.
This was the Land of Fields. Technically under Fire Country's shadow.
If Konoha nin suddenly noticed a massive Wood Release signature here, that would be… annoying.
As he worked, I scribbled notes nonstop. Several shadow clones bustled around me, each responsible for a different set of measurements.
One clone stepped forward, bowing slightly.
"First Hokage-sama, could you please use the exact same amount of chakra you'd use for a basic Fireball, and cast Wood Release instead?"
Hashirama tilted his head, confused, but didn't argue.
He adjusted his chakra output as requested and unleashed another Wood Release technique.
From the resulting data, the clone quickly reported size and growth rate.
One "Fireball amount" of chakra produced a wood construct—a tree about three meters tall and so thick two people would need to hug it together.
"Does this really matter?" Hashirama asked, genuinely baffled. "In a fight I just… use the jutsu and hit the enemy until they stop moving."
"That's exactly why I want this."
I smiled slightly and flipped to a fresh page.
"If we can determine the relationship between chakra output and jutsu power, we can calculate an optimal output. That way, we get the maximum effect for the minimum chakra cost."
In other words: efficiency.
I knew very well that ninjutsu wasn't purely mechanical.
Same jutsu:
Early Sasuke's Fireball
vs
Rinnegan Six Paths Sasuke's Fireball
There was no way those two had the same destructive power, even at "equal" chakra volume.
But that didn't mean there were no patterns.
And patterns could be modeled.
If we could eventually express it as something like:
Chakra quantity = X
Chakra "quality" (control, nature transformation, user aptitude) = Y
Ninjutsu output = f(X, Y)
Then—just like a buoyancy formula or F=ma—you could plug in your own numbers and find the sweet spot.
Of course, that wasn't something one Hashirama test could solve.
We'd need huge amounts of data:
Different ninjutsu, different users, different chakra natures, different ranks…
Then classify, fit curves, push the model, test it in the field…
Basically: a lifetime project.
For now, I just wanted baseline numbers from a "legendary outlier" like Hashirama. Future-me—or future-shadow-clone-me—could analyze it properly once we'd collected enough samples.
"Thank you for your cooperation, First Hokage-sama."
I gave him a respectful bow and released the Edo Tensei.
His body crumbled into dust and fragments. The chakra tether snapped.
I'd pushed him pretty hard—this reincarnated body's chakra capacity wasn't anywhere near his living prime.
"File all this under a separate box," I instructed the clones, tapping the notebook. "Label it: 'Hashirama – Wood Release Output Tests'."
They nodded and got to work, sorting and cataloguing everything.
As for me?
I still had a very temperamental thermobaric bomb project waiting for me. The whole "chakra efficiency formula" thing was just a seed for the future—a research branch I'd planted for later.
For now, explosions came first.