Gon slipped out of Muten Natsu's battered Gigai and returned to the toy lion.
"Good thing I'm a Modified Soul. If it were anyone else, they'd be dead by now."
As long as his pill-shaped core wasn't damaged, it didn't matter how badly the Gigai was wrecked.
"Natsu and Inoue have successfully infiltrated Seireitei," Uryū Ishida said as he consulted the black cat, Yoruichi. "Hakutōmon is already closed, and after what just happened, security inside must be even tighter now. What do we do next?"
"Follow me." The black cat Yoruichi turned and led the way. "Hakutōmon is no longer an option, and the nearest other gate would take ten days to reach on foot. So we'll have to enter without using a gate. We're going to find Kūkaku Shiba."
Ichigo Kurosaki remembered Muten Natsu mentioning the surname Shiba before.
"Kūkaku Shiba?"
"Yeah. Kūkaku Shiba has a way to get us inside." The black cat Yoruichi looked toward the distance. "We're here."
The group raised their heads, only to see a house standing alone in the middle of an empty plain. On either side of it were two stone arms.
Like massive hands growing straight out of the earth, they stood like pillars, holding up a red cloth banner. Written in black were four large characters:
[Kūkaku Shiba]
Along with the tall golden chimney behind the house, the whole scene was so visually overwhelming that no one knew what to say for a moment.
Just a moment ago, Ichigo Kurosaki had been wondering why someone so powerful would live somewhere so remote. Now he realized it was probably because other people couldn't handle such a bizarre aesthetic.
"Who are you?" Two burly men stepped forward, one dressed in gold, the other in silver-white. "You're dressed pretty weird!"
"These people are suspicious, Koganehiko." The brute glared viciously at them. "We can't let them pass, Shiroganehiko."
"Oh?" the black cat Yoruichi spoke up. "Is that so?"
"Yo... Yoruichi-sama!" Koganehiko instantly changed his attitude, and Shiroganehiko slid open the door.
Unlike a normal house, there was a staircase descending downward beyond the entrance.
"I never expected Yoruichi-sama to be with this bunch," Koganehiko said as he led the way. "My apologies. Please forgive us."
Ichigo Kurosaki: "..." What did he mean, this bunch?
"It's fine." The black cat Yoruichi leapt lightly down the steps. "I was also in the wrong for not giving notice in advance."
Koganehiko finally relaxed a little.
"You truly are broad-minded."
After descending the long staircase, Koganehiko stopped in front of a door.
"Please rest here for a moment."
A voice came from inside.
"Is that Koganehiko?"
"Yes, it's me!"
The voice asked again.
"Did an honored guest arrive?"
"Yes! Yes, indeed."
"Then what are you standing around for? Open the door!"
"I'm opening it now!" Koganehiko hurriedly slid the door open, revealing the scene inside.
A black-haired woman wearing a white headscarf sat with her legs crossed in front of a wall alcove hung with murals. Her dark eyes swept over the group, a faint smile tugging at her lips.
Her right arm ended at the upper arm, wrapped in white bandages, with a short blade tied to it.
On her remaining left upper arm was a black tattoo of the character [Kū], and she rested it casually against the armrest.
But what truly made it hard to look away was the way her thin red short top failed to contain her full figure, leaving an overwhelming cleavage.
The instant they saw her, Yasutora Sado, Uryū Ishida, and Ichigo Kurosaki all flushed red and awkwardly looked away, only to have their eyes drawn back again by the leg extending from the slit in her white long skirt.
Gon's eyes turned into hearts.
"Big sis—!"
Ichigo Kurosaki reacted instantly, grabbing Gon before he could leap forward.
"Long time no see, Yoruichi." Kūkaku Shiba glanced at the others. "What's with these brats?"
"Kūkaku, I came because I need you to do me a favor."
"As expected. Every time you show up, it's always this." Kūkaku Shiba clicked her tongue. "Is it hard?"
"I think it is."
"I'm most interested in things that are hard to pull off." Kūkaku Shiba's smile turned wicked. "Let's hear it."
...
Seireitei, Sixth Division Prison.
The iron bars that had been shut for a long time finally opened. Rukia Kuchiki turned her head.
"What is it, Renji?"
"The execution date has been moved up." Renji Abarai stepped forward, followed by four people in white robes carrying long staves. "It's been advanced to ten days from now. From here on out, you'll be held in the fourth deep cell of the Senzaikyū."
Red cords fluttered from the tops of their staves, linking to the collar around Rukia Kuchiki's neck that restrained her Reiryoku.
Black binding ropes extended from the collar, tying her arms behind her back.
The white cloth at the ends of the four red cords stitched together, forming a covering that slipped over her head.
Renji Abarai led the way in front, while the four white-robed figures held their staves and surrounded Rukia Kuchiki as they followed behind.
They slowly passed through tiled-roof buildings that rose higher and higher like a spiral staircase. The group stopped at the fourth structure, then crossed a suspension bridge hanging above most of Seireitei's buildings, entering a tall tower enclosed by the surrounding rooftops.
Once inside, the red cords dropped down, and the white cloth was pulled away.
The four white-robed figures collapsed to the ground.
Even Renji Abarai's expression turned grim.
This tower had Sekkiseki embedded within its walls, an exceedingly rare mineral capable of completely severing Reiryoku.
The Sealing Wall surrounding Seireitei was made from this very stone.
Sekkiseki produced fluctuations from its cut surfaces that could break down Reiryoku. After being adjusted by the Research and Development Institute, these fluctuations extended from the skies all the way down into the earth, forming an all-encompassing protective barrier that shielded Seireitei within.
Any Soul attempting to pass through would be torn apart by those fluctuations.
Within the Senzaikyū, although the fluctuations did not form a complete barrier, they still greatly suppressed the power of spiritual beings.
Renji Abarai looked toward the narrow window set into the wall.
"Rukia, can you see it?"
Rukia Kuchiki raised her head. Through the window, she could see a massive long-handled blade embedded into the cliffside, as well as the execution stand beside it.
Even from this distance, she could clearly sense just how enormous they were.
"That is the Sōkyoku," one of the white-robed figures finally said, having recovered somewhat. He stood and stepped forward as he spoke, sweeping his hand through the air. The black ropes binding Rukia Kuchiki's arms vanished at once.
"It is the pair of execution instruments that will be used to carry out your sentence. Every day, prisoners are made to look at it through this window, as a reminder to repent for their sins. That is where the name Senzaikyū comes from."
Rukia Kuchiki let her arms drop, staring at the horrifying instruments outside. Her voice drifted, distant and quiet.
"So... is that what Muten spent his time looking at?"
At the mention of Muten Natsu's name, even with the white cloth still present, Renji Abarai could sense their fear.
"Whoever designed this must have been very pleased with their own creativity." Rukia Kuchiki's lips curved into a faint smile. "What a shame. That person is going to be disappointed. Because the Muten Natsu in here would only be thinking... about how to destroy them in one go."
"Lieutenant Abarai, thank you for escorting the prisoner." The four white-robed figures clearly had no desire to continue speaking about Muten Natsu.
"Let's go."
Renji Abarai stared at Rukia Kuchiki's back.
"...Alright."
"Renji." Rukia Kuchiki suddenly spoke. "Didn't you say you were going to capture him? How did you have time to lead the transfer?"
"Don't you already know the answer?" Renji Abarai turned and began walking away. "Ryoka broke into Soul Society. One of them... was him."
"Idiot..." Rukia Kuchiki let out a long sigh, her face softening into a helpless smile. "I knew it would be like this."
Renji Abarai opened his mouth, but in the end, he still didn't tell her that Muten Natsu had been critically injured.
After leaving the Senzaikyū and parting ways with the four white-robed figures, Renji Abarai's mood sank even further.
Back then, the three of them had grown up together in Rukongai. They had entered Seireitei together.
And now, in the blink of an eye, two of the three had ended up inside the Senzaikyū.
"Hey—"
Hearing the call, Renji Abarai looked up.
A man wearing a captain's haori, thick black-framed glasses, and short brown hair was waving at him.
"Hi!"
Renji Abarai froze.
"Aizen-san..."
Captain of the Fifth Division, Sōsuke Aizen.
He had once been assigned by the Central 46 Compound to teach at the Shin'ō Academy for a period of time. Even after becoming a captain, he still served as a special calligraphy instructor at the academy.
Although calligraphy was only an elective, enrollment always exceeded capacity. Some students even had to stand in the hallway just to listen.
"Long time no see, Abarai." Sōsuke Aizen wore his usual gentle smile. "Could I have a word with you?"
Back at the Shin'ō Academy, Renji Abarai had once had his life saved by Sōsuke Aizen. Now, faced with the captain's invitation, he naturally didn't refuse.
He followed Aizen into a secluded storage room.
"Oh my, it feels like it's been a long time since we talked like this."
Sōsuke Aizen glanced around the room as if reminiscing. "How many years has it been since you were transferred to Kenpachi's squad? You're in the Sixth Division now, right?"
"Yes."
After graduating from the Shin'ō Academy, Renji Abarai had joined the Fifth Division under Sōsuke Aizen.
The Fifth Division was a rescue unit, responsible for assisting Shinigami and trainee Shinigami who encountered danger in the World of the Living.
However, all Fifth Division operations required approval from the First Division. Missions were rare to begin with, and every deployment meant mountains of reports and paperwork afterward.
Just when Renji Abarai was about to reach his limit, Sōsuke Aizen noticed his frustration and transferred him to a combat-specialized unit, the Eleventh Division.
The Eleventh Division was much simpler.
Fight Hollows. That was it.
Then, a few months ago, thanks to his outstanding performance, Renji Abarai was transferred again, this time to the Sixth Division, where he became its Lieutenant.
Transfers like Renji Abarai's were not uncommon.
Many members of the Gotei 13 had started out in the Fifth Division.
Some of them had even gone on to become Captains or Lieutenants.
It could be said that the Fifth Division excelled at cultivating talent.
Much of that was due to Sōsuke Aizen.
Regardless of who someone was, Captain Aizen treated everyone equally and never overlooked the feelings or potential of any squad member.
The Fifth Division's work was complicated and involved coordination with many other divisions.
Most Shinigami fresh out of the academy had no clear sense of what they were good at or where they truly belonged.
By working in the Fifth Division, they were able to come into contact with the duties of other squads.
Throughout that process, Sōsuke Aizen observed each member closely, taught them according to their strengths, helped them improve their abilities, gave them opportunities to gain experience, and selected suitable divisions for them before assisting with their transfers.
Aizen reached out and closed the door behind him.
"You should have already heard the news," he said calmly. "Muten Natsu has returned."
"...Yes."
"Don't be too guarded. I know you, Muten, and Rukia were close friends back in Rukongai."
Sōsuke Aizen's gaze grew deep. "From a friend's point of view, did you notice anything that felt off?"
"You mean the fact that he's still alive?"
Sōsuke Aizen shook his head.
"No. Him surviving wouldn't be strange at all. If Captain Unohana had intervened, Muten Natsu would have been extremely hard to kill."
"Then what do you mean...?"
"Everything."
A faint glimmer flashed through Sōsuke Aizen's eyes. "From the very beginning, up to now."
"Everything?"
"All information related to Muten Natsu has been erased. Let's piece it together."
Sōsuke Aizen spoke as if recounting a familiar list. "When you went to the Eleventh Division for training, Rukia was captured and taken to Hueco Mundo. Muten Natsu went in to save her, along with you and Takuma. After finally returning from Hueco Mundo, Muten Natsu was imprisoned in the Nest of Maggots."
That experience had been a brush with death. Renji Abarai remembered it all too clearly.
"After Captain Unohana brought him out, Muten Natsu was imprisoned again, this time for allegedly killing Takuma and Kaien. Later, when Rukia was in danger in Rukongai, Muten Natsu broke out to save her and was captured by her."
Sōsuke Aizen smiled faintly and shook his head. "He was sentenced to Sōkyoku execution, survived it, and was confined in Muken. After that, he slaughtered Central 46 and escaped to the World of the Living. And now, here we are. Rukia has been sentenced to Sōkyoku execution and is being held in the Senzaikyū. Do you see it?"
Renji Abarai frowned deeply.
"You saw how close Takuma and Muten Natsu were. Muten Natsu was too lazy to walk, so Takuma carried him every day. They were even called in by an instructor, who told Muten Natsu not to bully Takuma. And Kaien goes without saying. He was the one who helped Muten Natsu master his Shikai."
Sōsuke Aizen pinpointed the core of the issue. "Do you really believe Muten Natsu would kill them?"
"Of course not!"
Renji Abarai couldn't make sense of it. "But..."
"But the evidence is undeniable. The footage from the Surveillance Hall clearly shows him killing them."
Sōsuke Aizen finished the thought for him. "However, if Muten Natsu was framed, and you remove that segment, you'll find that everything points to a single conclusion."
Renji Abarai felt as if he'd been struck by lightning.
"Muten Natsu... was saving Rukia."
"And what if we add that segment back in?"
"Then someone was trying to frame him so he wouldn't be able to save Rukia."
Renji Abarai finally understood. "Someone wanted to harm Rukia. But why... and who...?"
"The division that uses the Surveillance Hall most frequently is the Twelfth Division's Research and Development Institute," Sōsuke Aizen said, providing the key detail. "But the Surveillance Hall existed long before the Research and Development Institute did. Even though the Institute uses it extensively for analysis, to the point that people joke [the Surveillance Hall is practically part of the Research and Development Institute], they only access a portion of its functions. In reality, the Surveillance Hall is operated in rotation by the noble families."