According to what Kasage knew, Hōraijima Island was hidden by a powerful Time Barrier.
The core of that barrier was something called the Resonance Cauldron.
Every fifty years, the barrier would weaken, allowing the island to reappear briefly in the world.
Right now, Uchiha Kasage was trying to locate that very barrier.
The good news was that, through the Mangekyō Sharingan's ability to perceive energy, she could clearly detect an abnormal area in the sea. The natural energy there was far more active than usual, confirming that something was hidden within that space.
The bad news—
The barrier itself could not be touched.
It felt intangible, like something that did not fully exist in this world.
Kasage narrowed her eyes slightly.
Most likely, Hōraijima Island had been shifted into another dimension.
"That means…" she murmured inwardly, "…it's not just hidden. It's displaced."
Kikyo, observing for a while, spoke softly.
"Let's leave for now. It seems we can only enter when the island appears."
Kasage didn't move.
"No… I'll try one more thing."
A faint excitement flickered in her eyes.
Kikyo looked at her, curious.
Kasage closed her right eye.
Her left eye opened—
Mangekyō Sharingan.
A surge of powerful chakra erupted.
"Kamui."
The space in front of them twisted instantly.
Ripples spread outward as a spiraling distortion formed, tearing open a passage into the Kamui dimension. The vortex rotated slowly, distorting everything around it as Kasage guided it across the sea.
Kikyo's eyes widened slightly.
"You're trying to use spatial distortion… to interfere with the barrier?"
Kasage nodded faintly, keeping her focus.
"That's right."
The swirling space continued to move, probing different points in the air.
She spoke calmly as she worked.
"The villagers said the island last appeared fifty years ago."
Kikyo nodded.
"That was when you and Inuyasha came here," Kasage continued. "Which means the cycle is almost complete. The barrier should be unstable right now."
The vortex shifted again, scanning.
"If that's the case… Kamui might disrupt it enough to reveal the island's location."
Kikyo watched in silence, her attention fixed on the distortion in space.
Then—
Kasage's gaze sharpened.
"Found it."
Kikyo immediately looked closer.
Within the center of the vortex, the scenery had changed.
It was no longer the open sea.
Instead—
A cliff covered in dense trees.
A faint outline of land began to emerge, like a mirage solidifying into reality.
"It's really there…" Kikyo whispered, surprised.
Kasage held the vortex steady, pouring more chakra into her eye technique.
The image grew clearer.
The shape of the island slowly revealed itself.
Hōraijima Island.
Kikyo frowned slightly.
"Even if we've found it… how do we enter?"
Kasage's lips curved faintly.
"With Kamui."
She continued channeling chakra, locking onto the coordinates of the hidden dimension.
"Kamui doesn't just connect to its own dimension," she explained. "It can resonate with others. Once I lock onto a dimension's position, I can forcibly open a path to it."
Kikyo looked at her in surprise.
"It can do that…?"
Kasage smiled faintly.
"That's only the left eye's ability."
Her voice carried quiet confidence.
"If you had seen the right eye in action, you'd understand why this technique is called Kamui."
Its power surpassed ordinary eye techniques.
It wasn't just movement—
It was control over space itself.
Still, it had limits.
Kasage knew she couldn't use this method to reach Kagome's world. That wasn't just another dimension—it was a completely separate world.
Trying to force a connection would drain her chakra instantly.
But Hōraijima Island was different.
It was simply hidden.
And that—
Could be broken into.
"Alright," Kasage said. "We're going in."
She wrapped an arm around Kikyo's waist, pulling her close.
Then she glanced at Entei.
"If you don't want to be torn apart by spatial distortion… don't move."
Entei stiffened instantly, its flames dimming as it froze in place.
Kasage focused completely.
Chakra surged into her Mangekyō Sharingan.
"Kamui."
The vortex expanded violently.
In an instant, it swallowed all three of them.
They vanished.
Elsewhere
In another dimension—
Above a crescent-shaped island—
Space twisted.
A vortex appeared out of nowhere, rapidly expanding.
The next moment, Kasage, Kikyo, and Entei emerged, suspended in midair.
Kikyo looked down.
Her eyes widened.
"We're… really here."
Below them lay Hōraijima Island, just as she remembered.
Lush forests.
Curved shores.
A quiet, isolated land surrounded by endless sea and thick fog.
She turned her head slightly.
"How do we leave?"
Kasage smiled lightly.
"If we can enter with Kamui… we can leave the same way."
Kikyo let out a small breath.
"That's reassuring."
Her gaze returned to the island, filled with curiosity.
This time—
She could finally explore it.
She gently patted Entei.
"Let's go down."
But before they descended—
Kasage spoke again, her tone calm but firm.
"Kikyo… you're wrong."
Kikyo looked at her.
"It's not 'the' island anymore."
A faint smile appeared on Kasage's face.
"It's our island now."
Kikyo stared at her for a moment—
Then smiled.
"You're right."
Their gazes met briefly, an unspoken understanding passing between them.
Below them—
Their new territory awaited.
Kasage's eyes shifted upward slightly.
Her expression cooled.
"But first… we deal with the ones who think they own it."
Kikyo nodded.
She had not forgotten.
Fifty years ago—
She had been attacked here.
Now—
That debt would be repaid.
Suddenly—
Boom!
The sea exploded below them.
A massive vortex formed in the water.
The next second, a blazing sphere of yokai energy shot upward at incredible speed, heading straight toward them.
Entei reacted instantly.
With a sharp movement, it sidestepped midair, narrowly avoiding the attack.
Kasage turned her head slightly, watching the projectile pass.
"They noticed us already…"
Her Rinnegan appeared.
She raised her hand.
"Banshō Ten'in."
Gravity twisted.
The flying sphere abruptly changed direction.
Pulled back by an invisible force, it curved through the air—
Then slammed back into the sea with even greater speed.
The surface erupted once more.
The battle—
Had begun.