Ensuring the number of squad members stays above a certain level is one of Seireitei's most important tasks, and the measures taken aren't limited to just appointing captains.
The continuous reforms of the Shin'ō Academy, the creation of Squad 4 specifically for medical care, and so on—all had this intention to some extent when they were founded, with the Shin'ō Academy being the most obvious example.
Of course, there have still been many instances in Seireitei's history where there was a severe shortage of personnel. To make up for the lack of combat power, and especially timely intelligence, Seireitei has resorted to quite a few dirty tricks.
The most recent instance traces back to the defection of Urahara Kisuke and seven other captain-level figures, along with three lieutenant-level figures, which led to a massive spike in the mortality rate of squad members. To counter this, Central 46 utilized the Gikongan developed by Urahara to execute an operation known as the "Spearhead Plan."
This plan used the Modified Souls from the Department of Research and Development as temporary combat power, deploying them as the main fighting force in battles against Hollows. To put it bluntly, it was treating Modified Souls as cannon fodder to reduce the Gotei 13's casualties. Modified Souls, as the name implies, are merely partial modifications of souls. As for where the raw materials came from...
But the reason for the lack of top-tier combat power can be traced back even further to the Menos invasion that lasted nearly twenty years. This directly caused most of the captains in Seireitei to run themselves ragged in the Rukongai day in and day out, which in turn provided Aizen with the most comfortable conditions for his experiments.
"If it weren't for that Menos invasion, Aizen's plan would never have gone so smoothly!" Those were Hirako's exact words back then.
Hearing this, Kōe could only sigh helplessly in his heart. *These two events aren't actually directly connected. Even if I hadn't stirred up trouble in Hueco Mundo, the wheels of history would have still rolled right over your face as usual. Just accept your fate, Hirako. Is it really that hard to admit your own mistakes? If all else fails, you could just blame it on Aizen being too strong.*
Of course, he couldn't actually say something so deserving of a beating out loud. So at the time, Kōe just politely agreed with a few words. But the moment he returned to Seireitei, karma came knocking.
The Spearhead Plan did indeed help the Gotei 13 survive their most difficult period, but such an inhumane practice was bound to draw condemnation; its abolition was practically inevitable. And once the Spearhead Plan was halted—whether voluntarily or forced—the Shin'ō Academy had to work hard to fill the resulting void in combat power.
Enrollment expansion—it was impossible to count how many times this massive expansion had begun. This didn't just include recruiting from a wider area in the Rukongai; it also involved the desperate measure of lowering admission standards, which could also be called a despicable tactic.
Compared to Kōe's time, the Shin'ō Academy had added an intriguing new rule: students who completed six years of study but failed the graduation exam were considered graduated but had to continue studying at the Academy until the day they passed the enlistment test and entered the Gotei 13.
Compared to before, this sounded a bit more responsible, but the reality was nowhere near that simple.
They were stockpiled, simplified Gikongan—or to put it more bluntly, reserve cannon fodder. For many squads, this was the sole purpose of these "inferior" students.
Of course, none of this really had any direct connection to Kōe. The most tangible impact the enrollment expansion had on him was that he had more students to teach!
In the past, Class 1 of the first year alone accounted for almost half the students in a single grade at the Shin'ō Academy, and he had to teach all their courses. The worst part was that his workload could actually be "expanded" too?! What a sin!
However, according to Hirako's logic, Kōe was the main culprit responsible for setting Seireitei back a thousand years. By Seireitei's standards, it was even more egregious: he, Urahara, and Yoruichi had single-handedly plunged Seireitei into the weakest, darkest period in its history. Forget about setting things back a few years—Seireitei had never been this destitute!
For Kōe, one could only say that suffering a death by a thousand cuts wouldn't be an overreaction. He was a sinner of historical proportions; making him an instructor at the Shin'ō Academy hardly even counted as a punishment.
But Kōe himself would absolutely never admit to that. As the saying goes, the wheels of history churn up billowing dust—how could mere human effort possibly stop them?
"Where did Captain Ichimaru go for his mission?" Kōe asked, pretending to be casual, though his eyes never left Aizen.
"The World of the Living. Recently, there have been multiple reports of stationed squad members dying in the World of the Living. Due to a lack of intelligence, we cannot determine the cause for now. Just to be safe, a captain was sent to investigate," Aizen answered unhurriedly. He then noticed Kōe staring at him and asked with a hint of uncertainty, "Is there something strange on my face, Mr. Chōzuka?"
"No."
"Then do you have any other questions? Feel free to speak your mind. I will gladly tell you anything I can."
"I don't really have any other questions, it's just..." Kōe's lips curled into a smile as he shifted his gaze away from Aizen. Clasping his hands behind his back, he drew out the end of his sentence, sounding like an old man out for a stroll. "It's just that compared to last time, Captain Aizen seems somewhat different."
During his five interactions with Aizen while co-teaching, Kōe had ostensibly been lecturing on filtering combat intelligence through sight, sound, and smell, but in reality, he was conducting an investigation into Kyōka Suigetsu.
He had made some gains, but because the core issue remained unresolved—namely, he still didn't know if Aizen accepted his invitation because Kyōka Suigetsu had lost its effect on him—Kōe constantly felt like he was wasting his effort.
Because of this, Kōe's focus had always been on Aizen himself. If he could catch some clues about the man secretly leaving Seireitei, he could analyze Aizen's thought process and logic based on his movements.
More importantly, the lives of Kaien and his wife were inextricably linked to Aizen's current actions. The most crucial factor in all of this was Aizen's campaign to conquer Hueco Mundo.
According to his deductions, Aizen wasn't conquering Hueco Mundo because his Shinigamification research had hit a bottleneck. On the contrary, it was because he had made a substantial breakthrough and therefore needed higher-grade experimental materials.
This wasn't some baseless guess; there was concrete evidence. Based on reports from the Shin'ō Academy and casual chats over drinks with Shunsui, Kōe learned about an accident Renji and the others had encountered during their Konsō field training a year ago.
Due to a sudden attack by special Hollows capable of hiding their Reiatsu, the first-year students participating in the Konsō training were nearly wiped out. Out of the three outstanding sixth-year students leading the group, only Hisagi Shūhei survived.
This incident had also occurred in the manga from his past life, and Kōe vaguely remembered that Aizen was the one who created those special Hollows.
They were clearly the products of Hollow Shinigamification. For ordinary Hollows, this was practically the absolute limit of what they could achieve. Any further, even with technological breakthroughs, ordinary Hollows wouldn't be able to handle the strain. It was the exact same principle as the soul disappearance incidents caused by the Hollowfication experiments in the Rukongai.
Under these circumstances, conquering Hueco Mundo was an inevitable choice. As for the exact timing of this conquest, Kōe couldn't predict it; he only knew it happened after Ichimaru Gin became a captain.
And once Las Noches changed hands, it wouldn't be long before Aizen created the Hollow capable of sealing a Zanpakutō's abilities. That would mark the beginning of the countdown for the lives of Kaien and his wife.
Now that Ichimaru Gin had become a captain and was simultaneously executing a mission in the World of the Living, did this mean Aizen had already begun setting foot in Hueco Mundo?
This was a question he had no choice but to ponder.