"Is this… wood?"
Obito held the vial in his hand and carefully examined the label stuck to it.
"Hashirama Cells."
The three of them were stunned.
"This is…"
"The First Hokage-sama's cells?!!"
"Wait, read the fine print carefully."
Obito read aloud, "Primary effects: repairing irreversible damage and curing various Kekkei Genkai diseases, with particularly strong effects on the Mangekyō Sharingan. After use, there is a certain chance of obtaining Hashirama Senju's Wood Release ability…"
"Wood Release!!"
"Irreversible damage?"
Young Kakashi and Rin Nohara spoke at the same time.
Their reactions felt a little too intense. Obito shot them a puzzled look but suppressed his curiosity and continued reading.
"Precautions: Due to the strong cellular devouring properties of Hashirama's cells, there is a high risk of backlash during use. It is strongly recommended to use together with a neutralizing agent."
He looked up at Rin and Kakashi.
"Is there something strange about this? Why are you two reacting like that?"
Back in the era when Konoha was first founded, they had already learned that Hashirama's cells could heal Sharingan-related damage. And the so-called neutralizing agent was essentially White Zetsu components.
Rin and Kakashi exchanged a glance.
In the end, Rin was the one who spoke.
"When you ran off earlier, Minato-sensei told us something."
"?!"
Obito's instincts flared immediately. This had to be related to him—or rather, to the him from another world—and it was important.
Rin continued, "In Naruto's world, someone killed the Kirigakure ninja who were chasing after that world's me and Kakashi. The power that person used was said to be Wood Release."
She deliberately avoided mentioning her own death in that world, focusing only on the Wood Release and the person who used it.
Young Kakashi followed up thoughtfully.
"My counterpart in the other world once said that 'Obito' died during the Kannabi Bridge mission, crushed by the Iwa ninja's Earth Release: Rock Lodging Destruction Technique… most of his body was smashed under falling boulders."
As Obito listened, he instinctively looked up at the massive rocks overhead, a chill running down his spine.
Rin felt the same unease.
"Let's leave this place first," she suggested.
Obito turned around to comfort her instead.
"It's fine. We already killed both Iwa ninja. It's not dangerous anymore."
Young Kakashi stood up and prepared to move.
"Don't lower your guard. They might still have reinforcements."
Obito and Rin stood as well, ready to follow him.
Rin looked at Obito worriedly.
"Try not to use your Mangekyō Sharingan unless you have to. Your eyes were bleeding again just now, weren't they?"
Obito remembered and took out some eye drops from his pack, putting in two drops.
"Once I use the Hashirama cells…" He squeezed his eyes, which still ached from using the Mangekyō Sharingan. "My body will be strengthened. Even better than the old ancestors' Eternal Mangekyō. The Kekkei Genkai disease won't be a problem anymore, and my eyes won't bleed again."
Then I'll be able to protect you both even better.
His voice was bright and full of energy, bringing a quiet sense of hope even to this place.
Holding the reward from the S-rank mission, he felt genuinely happy. Their teamwork—and this small step toward changing the future—filled him with excitement.
But he never could have imagined…
That those very words would accidentally trigger the conditions for using Hashirama's cells.
"I—am using—Hashirama's cells!"
The change came far too suddenly.
The bark inside the small glass vial began to grow at an alarming speed. In the blink of an eye, it expanded until it nearly burst the vial apart.
Crack!
A sharp sound rang out as a fracture appeared in the glass.
"Throw it away!" Young Kakashi shouted.
"Huh?!" Obito cried out. "But this is the S-rank mission reward—!"
That brief moment of hesitation was all it took.
The "Hashirama cells," which had already grown from a small piece of bark into a chunk of wood, surged like a parasite along Obito Uchiha's hand and burrowed straight into his body.
"Obito!"
"Obito!!!"
Kakashi and Rin shouted at the same time.
Obito wanted to tell them he was fine, that they shouldn't worry.
But what he saw instead were Rin and that stupid Kakashi's faces, even more terrified than before—and…
Their collapsing figures?
No…
It wasn't until he could only see their feet, then their knees bending toward the ground, that Obito realized it wasn't Rin and Kakashi who had fallen.
It was him.
...
Inside the stone cavern carved out by the Iwa ninja, suppressed groans of pain intertwined with roars that could no longer contain the agony.
Obito Uchiha, who had unknowingly become a host for Hashirama's cells, was twisting violently on the ground, completely devoid of dignity.
He convulsed in pain, as if his entire body were being overtaken by something alien.
"Ugh… aaaaah!!!"
Rin and Kakashi pinned Obito down. Seeing how much he was suffering, Rin pulled out a roll of gauze from her medical pouch and stuffed it into his mouth for him to bite down on.
It helped for a moment, but it would always slip out during his next scream.
This had already been going on for hours.
All three of them were in terrible shape.
Obito especially—his clothes were rumpled beyond recognition, his face smeared with dirt and sweat, so miserable it was almost painful to look at.
Young Kakashi snapped in frustration, "We're using the same S-rank mission reward! Why does Naruto get through it without anything happening, and you—why do you always end up like this, you idiot?!"
There was no malice in his words. It was concern turning into anger.
Obito drifted in and out of clarity from the pain. At times his thoughts were muddled, yet at others his mind felt unnaturally sharp. Hearing Kakashi's words, resentment and bitterness welled up inside him.
Was this some kind of punishment because the Obito from another world had become an unforgivable villain, and he was being dragged into it too?
If only he'd never said anything about using Hashirama's cells.
Another wave hit, every single cell in his body resisting the devouring force of the cells within him.
The pain made his Mangekyō Sharingan and three-tomoe Sharingan open and close in cycles. Only when the pain eased slightly would his eyes return to the ordinary black of the Uchiha.
If only he hadn't touched his ninja pouch.
If he'd finished the mission and gone to find Minato-sensei before making any decisions, maybe none of this would have happened.
And yet, even as the pain pushed him toward delirium, one thought stayed firmly rooted in his mind.
No matter what, he had to live. He had to change the ending of that other world. Rin and Kakashi couldn't be left behind. If they were going back, it had to be all three of them returning to Konoha together.
"Ka… Kakashi… what time… is it…?"
When the pain eased slightly, Obito forced out the question.
He knew that if this dragged on any longer, Iwagakure reinforcements would definitely arrive.
"Not even a full day yet," Kakashi replied.
Obito tried to prop himself up. "My body… it feels like every single cell… is being eaten away. The First Hokage's cells are like… some kind of contagious disease… trying to infect all three hundred trillion cells in my body… turning them all into the same thing…"
He had to gasp for air after almost every word. Even so, this was the best state he'd been in so far.
"They're like sentient monsters… those First Hokage cells… ahhh!"
The moment he finished speaking, another surge of pain crashed down on him, turning his words into a heart-rending scream.
Rin examined the chakra inside Obito's body. The chakra carried by Hashirama's cells was aggressively invading his own.
She had always known that Obito cried easily, but that he possessed an incredible stubbornness when it mattered.
Only now, as a medical ninja observing his internal state, did she realize that his willpower was far stronger than she had ever imagined—by hundreds, even thousands of times.
The First Hokage's cells were like billions upon billions of enemies, simultaneously attacking Obito's skin, muscles, bones, blood, organs, pain receptors, and sensory system.
In this state, Obito couldn't afford to lose consciousness.
Once he did…
Rin could already imagine the outcome. It was exactly what Jiraiya-sama had once described—the fate of Orochimaru's experimental subjects.
Consumed by Hashirama-sama's cells, Wood Release would erupt from the inside out. As the internal organs were crushed and warped by uncontrolled Wood Release, death would come in a twisted, agonizing form.
Knowing this made Rin's heart ache unbearably. She wiped away her tears and continued to use what little strength she had to help stabilize Obito's chakra. But at best, it was only a small comfort—whether she did it or not barely changed anything.
She shared her thoughts with Kakashi, who grew so anxious he slammed his fist into a nearby rock.
"Unless we can find that White Zetsu right now!!"
But where was White Zetsu? What did it even look like? They had no idea.
Just then, faint movement sounded outside.
Kakashi instantly tensed.
They desperately hoped it was Minato-sensei.
After all, they were only twelve or thirteen years old. Obito's condition was far too abnormal. Even if Minato arrived, there was no guarantee he could fix it—but right now, they still needed an adult to rely on.
However…
Misfortune never comes alone.
The people outside were Iwa ninja who had discovered the severed head lying in the grass and the headless corpse hanging from the tree branch.
Worse still, there were many of them—at least a dozen.
And based on what they saw outside, they had already deduced that Konoha ninja were hiding inside their base.
The dozen or so Iwa ninja said nothing.
Inside the stronghold, Kakashi stood in front of Obito and Rin, gripping his Chakra Blade as a shield.
He had assumed that since they hadn't seen that spiky-haired Iwa ninja, the enemy wouldn't recklessly use large-scale ninjutsu to carpet-bomb the area.
But he had still underestimated the methods of those Iwa jōnin.
They couldn't determine how many Konoha ninja were inside the base, nor their identities or strength. Since they were enemies, the safest approach was simple—kill them all. As for Kakkō, even if he wasn't dead, he had almost certainly been tortured into revealing village secrets. By that standard alone, he deserved to die as well.
More than a dozen Iwa ninja exchanged brief looks.
After forming several hand seals…
They shouted in unison:
"Earth Release: Tearing Earth Turning Palm!!"
This was a technique that concentrated chakra into the palms, striking the ground to fracture the earth and attack enemies through collapsing terrain.
With more than a dozen jōnin using it at the same time, the stone stronghold—constructed through ninjutsu in the first place—collapsed instantly. Massive, unstable boulders began crashing down one after another.
All three of them panicked.
Wasn't this exactly the same situation Kakashi had faced in the other world?!
Knowing that Obito had once died beneath falling rocks, the three of them felt an overwhelming sense of dread toward the collapsing stone.
Kakashi hadn't lost an eye in the earlier fight, but Obito's body was nearly unable to move due to the erosion of Hashirama's cells.
What should they do?!
Rin and Kakashi each supported Obito from one side.
No matter what, they had to get out of here first!
Escape!
Return to Konoha together!
And if they couldn't…
Then they would stay behind together!
At that moment, Rin and Kakashi fixed their determined gazes on the cave entrance, which was still some distance away.
"Rin."
At the same time, Obito suddenly spoke. His voice was far calmer than either of theirs.
"Kakashi."
"Hold on to me. Don't let go."
He said it plainly.
"What are you planning to do?!" Kakashi demanded.
"Obito! Don't do anything reckless!" Rin's voice turned sharp with panic.
Obito didn't answer. He simply closed his eyes tightly and lowered his head.
The next instant, when he lifted his head and opened his eyes again—
The black tomoe within his crimson Sharingan contracted in an instant, transforming into a unique pattern formed by three scythe-like shapes.
The Mangekyō Sharingan.
He wrapped his arms tightly around Kakashi's and Rin's waists, pulling them into his own intangibility.
For the next several seconds, he ran straight through the falling boulders.
Whether it was the shattered stone beneath their feet, the obstacles at their sides, or the sand, dust, and massive rocks crashing down from above—
Everything passed straight through their bodies, leaving them completely unharmed.
During those few seconds, Kakashi and Rin could do nothing but cling tightly to Obito and run with him. Experiencing intangibility for the first time, their minds were almost blank.
They watched themselves rush straight into a freshly fallen boulder, only to pass through it and burst out the other side.
They felt enormous stones slam through their bodies and crash down at their feet.
Until Obito finally carried them out of the collapsing rubble.
The intangibility faded.
Only then did Rin and Kakashi come back to themselves, as if they had just walked through a genjutsu.
The Iwa ninja staring at them from the outside were utterly stunned, unable to comprehend how they had escaped from inside.
But there was no time for questions.
Before Rin and Kakashi could even begin to relax—
A shrill, agonized scream tore from Obito's throat.
Immediately after—
Bang!
Rin and Kakashi snapped their heads toward the sound. From the corner of their eyes, they saw—
From Obito's back, massive wooden growths burst out like bamboo shoots breaking through the ground, spraying blood as they tore through muscle and skin and erupted from his body. In the span of a single second, they grew into enormous wooden spikes more than two meters long.
"Obito!!!!"