The underground training area beneath the Urahara Shop extended outward in a vast, cavernous space, its size easily rivaling the underground facility used by the Visored.
When Kurotsuki Renya arrived, Kurosaki Ichigo, Ishida Uryū, Chad (Sado) Yasutora, and Inoue Orihime had already gathered.
After entering, Renya pulled the hood of his specialized cloak over his head, and his entire figure faded from sight.
Renya had tested this cloak many times. Originally created by Urahara Kisuke to suppress spiritual pressure, it had later been enhanced with advanced Kidō modifications—some originally researched by Aizen—allowing complete visual erasure.
As long as Renya remained silent, even spiritually aware individuals would have difficulty detecting him.
He concealed his presence deliberately. The moment Ichigo drew attention in Soul Society, Renya planned to carry out his own operation.
Renya moved silently behind Urahara and lightly tapped his shoulder.
Urahara gave a small nod.
"Alright. It's about time—let's begin."
With a snap of Urahara's fingers, three massive stone pillars rose from the ground, slamming into place and forming a triangular archway.
"The Senkaimon," Urahara explained. "All travel into Soul Society goes through here. But physical objects can't pass through as they are—they must be converted into Reishi."
Ichigo, visibly anxious, stepped forward.
"Then let's hurry!"
Urahara's expression hardened.
"Listen carefully. Once this gate opens, you'll only have four minutes to reach the other side. If you fail, you'll be trapped in the Dangai Precipice World. The Cleaners who patrol the Dangai will bind you, and escape becomes nearly impossible. They sweep through the boundary every seven days."
He swept his fan downward.
"So once we enter, stay close."
Yoruichi—currently in her black cat form—added sharply:
"Are you ready? Entering Seireitei this way could mean death."
"I'll save Kuchiki Rukia. No matter what," Ichigo answered without hesitation.
"Then let's start."
Urahara and Tessai positioned themselves at opposite ends of the gate, both activating Kidō seals that locked into the ground.
With a thunderous burst of spiritual pressure, the Senkaimon flared open, emitting a blinding white light.
"Go! Now!" Yoruichi shouted.
She leapt in first. Ichigo and the others followed.
Renya slipped in last.
Inside, they emerged into the long, unstable corridor of the Dangai. Streams of highly pressurized reishi flowed violently along the walls.
"Run!" Yoruichi commanded, sprinting ahead. Renya kept pace effortlessly.
The danger of the Dangai wasn't the complexity—it was the speed. As long as one ran with full effort, being bound by the Kōryū was avoidable.
But Ishida's cloak dragged behind him, and the Kōryū's flowing mass caught onto it.
Ichigo reached for Zangetsu, but Yoruichi shouted:
"Don't draw it! Releasing spiritual pressure will make the Kōryū swallow all of you!"
Just as the Kōryū devoured half of Ishida's cloak, Chad surged forward, tore it free, and lifted Ishida onto his back.
Meanwhile, alarms suddenly blared throughout Seireitei.
"A spatial distortion detected in the Western outer sector! Warning level: Third District through Eighth District!"
Because Urahara's Senkaimon had not been officially registered with Central 46, the spatial fluctuation was instantly flagged by the Gotei 13.
Shinigami patrol squads mobilized, rushing toward the disturbance near West Rukongai.
Back in the Dangai, a deep rumbling echoed from behind them—a massive shadow barreling forward, swallowing everything in its path.
"Damn it—the Cleaner!" Yoruichi yelled. "Run! Don't let it touch you!"
Renya glanced back, intrigued by the massive, sweeping construct. Even from a distance, the pressure it emitted was overwhelming.
So this is the Cleaner Aizen destroys one day… impressive.
The Cleaner closed in rapidly. Just as it was about to overtake them, Orihime thrust out her hands.
"Santen Kesshun!"
Her three-point shield materialized, stopping the Cleaner just long enough for everyone to burst out of the Dangai and into the exit point.
"We made it…" Ichigo gasped, collapsing onto the ground.
The group rested, while Yoruichi reprimanded Orihime for using her power recklessly.
"Is it over there?" Ichigo asked after catching his breath.
Then, without waiting, he bolted ahead.
"Idiot—wait!" Yoruichi shouted, but Ichigo had already run to the far end.
A massive wooden gate slammed down from the sky, blocking his path.
The gigantic guardian Jidanbō appeared before them—the keeper of the West Gate, Hakutōmon.
Just as in canon, Ichigo challenged Jidanbō, defeating him through brute strength and determination.
Jidanbō opened the gate for them, but immediately afterward, Ichimaru Gin appeared, effortlessly sealing the gate with a single slash—injuring Jidanbō and sending Ichigo flying with his deceptive, venomous smile.
Their attempt to enter through the front had failed.
Orihime used her ability to heal Jidanbō, and with his gratitude, the group was taken in by a local elder of the nearby Rukongai district to rest.
While the others settled, Yoruichi approached Renya quietly.
"We'll need the Shiba Family's cannon-fire launcher to break into Seireitei. Kuukaku should help us… but if her brother—Shiba Kaien—is home…"
Renya smiled faintly.
"Don't worry. They won't oppose you."
Renya knew from future events: Captain Ukitake chose to save Rukia because he imagined what Kaien would have done.
Shiba Kaien would risk anything for his own people.
Right now, Kaien was likely exhausting every favor he had within Seireitei to intervene in Rukia's case.
Renya led Yoruichi toward the Shiba estate.
Urahara's gate only opened to West Rukongai, so reaching the North Third District required a long journey.
"Enough rest," Yoruichi told Ichigo's group. "We're moving."
Because of the altered events in this timeline—Kaien having survived—the group never encountered Shiba Ganju, who was normally the one to fight Ichigo.
By evening, they finally reached the Shiba household.
"Is this the place?" Ichigo asked.
"Yes," Yoruichi replied. "Knock."
Ichigo knocked, and the door opened to reveal two muscular figures.
It was Koganehiko and Shiroganehiko, loyal attendants of the Shiba family.
Before they could question Ichigo, Yoruichi leapt from his shoulder.
"It's me."
Both attendants straightened instantly.
"Lady Yoruichi! Please, enter!"
They escorted the group inside. Renya followed silently.
In the back room sat Shiba Kukaku, cross-legged, smoking her pipe.
Renya's chest tightened. After thirty years, seeing Kukaku again filled him with emotion.
Yoruichi smiled.
"Kukaku, long time no see. We need your help."
Kukaku listened carefully. When she learned their goal was to rescue Rukia, her brows narrowed.
"You plan to break into Seireitei…? You know this violates Gotei law."
In this timeline—where Kaien Shiba is alive and serves as a Captain—Kukaku held no hatred toward the Gotei 13.
Helping outsiders break into Seireitei could affect Kaien's position and their entire clan.
Renya feared Kukaku would refuse.
But she exhaled smoke and gave a small smile.
"Rukia Kuchiki served under my brother. And Kaien is already fighting to save her. Besides… she saved another brother of mine. He's gone, but if he were alive, he'd save her without hesitation. So—I'll help."
Renya froze.
Another brother… that was him.
Kukaku remembered everything he had ever told her about his life in Rukongai, about Renji and Rukia.
Her loyalty moved him deeply.
Yoruichi bowed slightly.
"Thank you. Let my group rest. There's something I need to discuss privately."
"Koganehiko! Shiroganehiko! Show them to their rooms."
Once they left, Yoruichi turned serious.
"Kukaku… stay calm, no matter what you see."
"Calm? What are you talking abou—"
She turned to face Renya.
Her pipe slipped from her fingers.
Her eyes widened.
"K-Kurotsuki Renya…? How… why is it you!?"