The days passed calmly and without urgency.
During this time, aside from staying inside his wooden house, Uchiha Kasage would occasionally visit the nearby human town mentioned by the Mamedanuki tribe, gathering supplies for daily life.
Most of his time, however, was devoted to cultivating Sage Mode.
Training Taijutsu and Ninjutsu within an Edo Tensei body produced minimal results, but he made a far more valuable discovery—the Natural Energy of this world was incredibly active. As a result, his Sage Mode training progressed far more efficiently than it ever had in the Naruto world.
The Sage Mode he cultivated did not originate from Mount Myōboku.
In truth, he had never even had the chance to learn it there.
With his identity as an Uchiha—and one who had lived during the era of the Third Hokage—there was no possibility that someone like Jiraiya would have taken him to Mount Myōboku.
Jiraiya, a disciple of the Second Hokage's lineage and a loyal supporter of Konoha, could never fully trust an Uchiha. The long-standing tension between the Uchiha Clan and the village's leadership made such a relationship impossible.
Kasage himself understood this clearly.
Even Naruto, with his unique nature, had earned Jiraiya's trust over time. But for an Uchiha like him, things would have been entirely different.
Jiraiya would never have taught him.
Because of that, his Sage Mode came from a completely different source—
Ryūchi Cave.
He had obtained the opportunity to learn it only after completing a dangerous mission under Orochimaru. As a reward, he had been allowed to enter Ryūchi Cave and learn the White Snake Sage Mode.
Unlike the toad-based Senjutsu of Mount Myōboku, the Sage Mode of Ryūchi Cave was far more dangerous and far more demanding.
But it suited him.
And more importantly—
His talent for it was exceptional.
Far beyond what he had expected.
Even back then, his mastery had already surpassed many practitioners. Now, after arriving in this world filled with abundant Natural Energy, his progress had accelerated even further.
The difficulty of entering Sage Mode had drastically decreased, and the duration he could maintain it had increased significantly.
More importantly, his control had reached a refined level.
The longer he cultivated, the smoother his transitions became. What once required careful stillness now required only brief concentration.
The physical changes associated with Sage Mode had also become minimal.
Only his slightly slit pupils and a faint, almost imperceptible aura hinted at the transformation—nothing grotesque, nothing exaggerated.
A perfect balance.
"Perhaps one day… I can reach the level of activating Sage Mode instantly."
That thought lingered in his mind, pushing him to continue refining his control.
At that moment, Uchiha Kasage sat cross-legged on the balcony floor.
Invisible currents of Natural Energy gathered around him, flowing into his body like a silent tide. His presence blended seamlessly with the surrounding mountains and forest, his perception extending outward in all directions.
Then—
His senses sharpened.
A relatively strong yokai aura was approaching rapidly, accompanied by several weaker ones.
Those weaker presences were familiar—the Mamedanuki.
"It seems that cat yokai has finally arrived."
Uchiha Kasage opened his eyes.
The faint signs of Sage Mode faded instantly as the gathered Natural Energy dispersed. He stood up, pushed open the balcony door, and leapt down from the second floor.
Landing lightly, he dashed toward the direction of the incoming presence.
Soon, a red figure appeared between the trees, moving swiftly through the forest with several Mamedanuki following behind.
She had short, sharp crimson hair and equally sharp red eyes. Her figure was tall and slender, her movements fluid yet powerful.
She wore a white short top and black trousers, covered by a brown hide miniskirt. A bright red belt wrapped around her waist, and knee-high fur boots completed her outfit.
Behind her, a brown cat tail swayed naturally with each step.
"Natsuarashi of the Leopard Cat Clan…"
Uchiha Kasage recognized her immediately.
Her appearance and aura matched perfectly—one of the Four Heavenly Kings of the Leopard Cat Clan.
As he observed her, Natsuarashi suddenly paused. Her nose twitched slightly before she snapped her gaze upward.
Their eyes met.
She immediately grew wary.
"Hey! Who are you? Why are you blocking the way?" she demanded, stopping in place and taking a defensive stance.
Uchiha Kasage didn't answer immediately.
Instead, he calmly looked her up and down, his gaze lingering briefly on her tail before he spoke.
"You're a cat yokai… but no ears. That's a shame."
"How irritating!" Natsuarashi snapped, her eyes narrowing sharply. Her claws extended with a faint metallic glint. "Stop messing around. Who are you, and what do you want?"
If she hadn't come alone into this territory for reconnaissance, she would have already attacked.
Uchiha Kasage finally moved.
He pulled out a shard of the Shikon Jewel from his pouch and held it between his fingers. Under the sunlight, the pink crystal shimmered brilliantly.
Natsuarashi's attention locked onto it instantly.
"My name is Uchiha Kasage," he said calmly. A faint smile appeared on his lips. "And you… you've been looking for this, haven't you?"
"That's… a shard of the Shikon Jewel?" she asked, her eyes lighting up.
"You don't even recognize it?" he teased lightly. "Have you been searching blindly all this time?"
"Shut up!" Her cheeks flushed with anger. She bared her fangs. "Hand it over, or I'll kill you!"
Kasage casually tossed the shard into the air and caught it again.
Natsuarashi's gaze followed it involuntarily.
"Tell me," he continued, "what do you want it for?"
"Stop talking nonsense!" she snapped. "I'm from the Leopard Cat Clan—not some stray you can mock!"
Her claws pointed directly at him.
"Hand it over. Now."
Kasage caught the shard mid-air once more… and put it away.
"This isn't something you should play with," he said calmly. "So no."
That was the last straw.
"You bastard!"
Her aura exploded outward.
"I am a Leopard Cat—not some pet that chases mice!"
In an instant, she moved.
Her body became a red blur as she lunged forward, claws aimed straight for his face.
Kasage stepped back slightly—effortlessly dodging.
Without missing a beat, Natsuarashi kicked off a tree, twisting mid-air and redirecting her attack toward his neck with deadly precision.
Once again—
Kasage leaned back just enough to avoid it.
Calm. Untouched.
He even raised an eyebrow, as if mildly entertained.