In fact, the fundamental reason why Aizen became the Lieutenant of the 5th Division was precisely because the Captain of the 5th Division, Hirako Shinji, wanted to keep him close, under his personal surveillance.
However, judging by how events unfolded later, it remains unclear whether Shinji genuinely sensed something about Aizen or if Aizen intentionally allowed Hirako to perceive it.
But none of this had anything to do with Kyoya.
At least, before he had grown strong enough, he had no intention of getting too involved with troublesome figures like Aizen.
On one hand, his Observation Haki had not yet reached the level of [Hearing the Voice of All Things] or [Future Sight], meaning he couldn't maintain clarity under the influence of Aizen's [Kyoka Suigetsu].
On the other hand, Kyoya himself was an anomaly in the world of the Shinigami due to the One Piece Achievement System. If he were to attract Aizen's research interests, he couldn't guarantee that he wouldn't end up as one of Aizen's lab subjects.
Thus, when faced with Ichimaru Gin's invitation, Kyoya decisively shook his head in refusal.
"I'm sorry, Ichimaru-senpai."
"I already have a division in mind that I want to join, so I'll have to decline your kind offer."
"Is that so…"
Upon hearing Kyoya's rejection, Gin tucked his hands into the sleeves of his Shihakusho, fell silent for a few seconds, and then grinned, "Well, someone as talented as you, Kyoya, must already have a clear plan for your future path."
"My invitation must have been too sudden."
"But I'm curious… which division are you planning to join?"
"Of course, the 11th Division!"
Seeing that Gin truly had no intention of continuing the fight, Kyoya released his Zanpakuto's Partial Shikai. The golden light dissipated, revealing the sword's original form.
Returning his Zanpakuto to its sheath at his waist, Kyoya said, "Ichimaru-senpai, my talents lie almost entirely in Zanjutsu."
"And when it comes to mastering Zanjutsu, combat is undoubtedly the fastest path to improvement."
"The 11th Division is a combat-focused division, one that provides the most opportunities for real battles. It's the best fit for my future growth."
"So, as long as I successfully graduate from the Shin'o Academy, the 11th Division will be my top choice."
This wasn't a lie to Gin.
While it was true that joining the 3rd, 5th, 7th, 9th, or 10th Division would be the optimal path if Kyoya wanted to become a Captain of the Gotei 13 in the shortest time possible, the future held complications.
Within the next few decades, Aizen's Hollowfication experiments would infect the Captains of those divisions… 3rd Division's Otoribashi Rojuro, 5th Division's Hirako Shinji, 7th Division's Aikawa Rabu, and 9th Division's Muguruma Kensei… forcing them to flee with Urahara Kisuke and Shihoin Yoruichi's help and form the [Visored].
Thus, the Captain positions of the 3rd, 5th, 7th, and 9th Divisions would become vacant.
The 2nd Division is originally the Shihoin Clan's Onmitsukido Unit.
Si even if Yoruichi left, they would never accept Kyoya as the Captain.
Similarly, no matter how strong Kyoya became, he could never surpass Kurotsuchi Mayuri for the Captain's position of the 12th Division. After all, the 12th Division was the Research and Development Institute, where only scientific prowess could earn the respect of its officers and members.
As for the 10th Division, the incident involving Aizen's artificial Vasto Lorde, White, would drag its captain, Isshin Shiba, into the chaos.
Therefore, if Kyoya wanted to become a captain, joining the 3rd, 5th, 7th, 9th, or 10th Division would be the best choice.
But before that, Kyoya needed to raise his strength to a level where he could be nominated for the position of Captain.
Becoming an official division member, then a seated officer, a high-ranking officer, a Lieutenant, and finally a Captain would undoubtedly trigger certain achievements, granting Kyoya rewards from the system.
If he joined other divisions, even if his strength was sufficient, he would still need to grind through seniority for promotions.
Take Hitsugaya Toshiro, the future Captain of the 10th Division, for example. By the time he joined the 10th Division, his strength already surpassed Rangiku's.
However, the Lieutenant of the 10th Division is still Rangiku.
Though Hitsugaya was groomed by Shiba as the 10th Division's future Captain, he was still only the third seat at the time.
Only the 11th Division valued strength above all else.
As long as Kyoya was strong enough, he could challenge any seated officer, Lieutenant, or even the Captain at any time… and if he won, he would take their position.
Even if Kyoya ultimately failed to defeat the 11th Division's Captain and claim the position, as long as he demonstrated Captain-level strength during their battle, he would be the first candidate the other Captains considered whenever a vacancy arose.
After all, if only one or two captain positions were empty, the Gotei 13 wouldn't be too concerned.
There were already non-Captains with Captain-level strength in the Gotei 13.
In emergencies, they could temporarily serve as acting captains.
If there was no urgency, waiting a few decades would allow each division to nurture its own Captain.
But a single incident that wiped out six Captains and the Kido Corps' commander would be a devastating blow to the Gotei 13. The Seireitei would need to fill those positions as quickly as possible to restore morale among the lower-ranked Shinigami.
At the very least, if Kyoya hadn't risen to Lieutenant in the 11th Division within ten years, he could always transfer to one of those other divisions as a third seat or Lieutenant.
After that, as long as he avoided getting involved in the investigations when Aizen 'removed' those Captains, his promotion to Captain would be all but guaranteed.
"The 11th Division, huh?"
"That does seem like a good fit for you, Kyoya-kun."
"Well then, I'll wish you the best of luck in joining the 11th Division."
"See you~"
With that, Gin waved at Kyoya and vanished into the night.
"Haaah…"
Only when Gin was completely out of his Observation Haki's range did Kyoya finally let out a sigh of relief.
'So strong!'
That brief battle had made Kyoya fully aware of the gap between himself and Gin.
Even with Observation Haki, he had been completely suppressed in their fight.
The difference in their base stats was simply too vast.
Even if Kyoya could sense Ichimaru's movements with Observation Haki, his body couldn't react fast enough to keep up.
Though he had used Partial Shikai, he knew that if the fight had continued, he would have lost.
The gap between 8th-class Reiryoku and 5th-class Reiryoku was one factor.
But the biggest reason is, his opponent was Ichimaru Gin.