As for Kyoraku, he was naturally a lazy person and didn't have much ambition for the Captain-Commander's position. In the original work, he succeeded to the position only because after Yamamoto died in battle, no one was more suitable than him, and also due to the Soul King's command.
At this point, Ukitake couldn't help but say, "You two, really... This is the Captain-Commander position we're talking about, and you don't care at all. Are you showing off in front of me? Clearly, I'm also Genryusai-sensei's student, but even if I wanted to be Captain-Commander, I wouldn't have the chance... cough, cough..."
"Hahaha, Ukitake, if you want to be Captain-Commander, you'd better cure your body first!" Toshiro couldn't help but laugh.
Ukitake, as Yamamoto's disciple, possessed strength even comparable to Kyoraku. Coupled with his serious and responsible attitude, he was originally even more suitable to be Captain-Commander than Kyoraku. However, due to his poor health, not only was he unfit to be Captain-Commander, he wasn't even a candidate.
When Yamamoto considered successors for the Captain-Commander's position, he simply overlooked him. After all, you couldn't choose someone constantly plagued by illness to be Captain-Commander.
"Shunsui, you probably know quite a bit about the Hueco Mundo Expeditionary Force. Tell me in detail," Toshiro asked Kyoraku after the joking was over.
As one of the most senior Captains of the Gotei 13, Kyoraku should know a lot about the Hueco Mundo Expeditionary Force.
"It seems you've decided to go to Hueco Mundo," Kyoraku said.
"Yeah, you're right. If I want to improve my strength quickly, battle is indeed the best way," Toshiro nodded.
"Mm, alright."
Kyoraku nodded: "The first time the Soul Society dispatched an expeditionary force to Hueco Mundo was several hundred years ago. I remember the first commander of the Hueco Mundo Expeditionary Force was a Shinigami named Ashido."
Kyoraku wore a nostalgic expression.
"What? Ashido?" Toshiro exclaimed in surprise.
"Hmm? What's wrong, Toshiro? Have you heard of him?" Kyoraku asked, puzzled.
The first commander of the Hueco Mundo Expeditionary Force, Ashido, leading the campaign to Hueco Mundo, happened several hundred years ago.
Not many in the Soul Society should know about him, let alone a Shinigami like Toshiro who isn't even a hundred years old. Logically, Toshiro shouldn't know about this. But judging by Toshiro's reaction, he seemed to have heard of Ashido.
"No... I haven't," Toshiro denied.
Toshiro did know about Ashido, but that was from watching the anime in his previous life. He couldn't very well tell Kyoraku he learned it from an anime and that they were all anime characters.
'But how did Ashido become the first commander of the Hueco Mundo Expeditionary Force? I remember in the anime, he and his comrades accidentally entered Hueco Mundo while chasing Hollows, right?' Toshiro wondered internally.
Toshiro remembered the character Ashido only from the anime. He wasn't in the manga.
In the anime, Ashido and his comrades were chasing Hollows. Judging by the surrounding scenery and architecture, they should have been in the Soul Society.
At that time, the Hollows were being beaten back by Ashido and his comrades, so the Hollows escaped back to Hueco Mundo through a Garganta.
Ashido and his comrades pursued and also entered through the Garganta. By the time they realized it, they were already in Hueco Mundo, specifically in the Forest of Menos. Then, they faced almost endless Hollows...
'Could it be that the first commander of the Hueco Mundo Expeditionary Force, Ashido, and the Ashido from the anime aren't the same person?' Toshiro wondered.
What Toshiro didn't know was that although Ashido wasn't in the manga, official novels mentioned that several hundred years ago, a Shinigami named Ashido did lead a campaign to Hueco Mundo. Whether the anime's Ashido and the official novel's Ashido are the same person... perhaps only by asking the anime's Ashido in person could Toshiro find out.
Although Kyoraku noticed Toshiro's slightly odd expression, suggesting he might know about Ashido, since Toshiro didn't want to talk about it, Kyoraku didn't press him.
"Speaking of which, the first expeditionary force commander, Ashido, led the campaign to Hueco Mundo but later disappeared. However, I believe he will return. Toshiro, when you go to Hueco Mundo this time, if possible, help me look for him," Kyoraku requested.
"Oh? Is this Ashido a friend of yours, Shunsui?" Toshiro asked.
"Well, not exactly my friend. But he was the close friend of my good friend, Kuruyashiki Kenpachi," Kyoraku explained.
"Kuruyashiki Kenpachi?" Toshiro asked, puzzled.
"Yeah, Kuruyashiki Kenpachi was the 7th Kenpachi and also my good friend. After Ashido disappeared in Hueco Mundo, Kuruyashiki always believed Ashido was still alive."
At this point, Kyoraku looked somewhat sad.
Toshiro knew why. To become Kenpachi, one had to defeat the current Kenpachi.
Although it wasn't explicitly stated that one had to kill the previous Kenpachi to become the new one, no defeated Kenpachi had ever survived a challenge. So, Toshiro understood that Kyoraku's good friend, Kuruyashiki Kenpachi was probably dead.
As for Unohana, she likely gave up the Kenpachi name voluntarily back then and became Captain of the 4th Division.
Kuruyashiki was the 7th Kenpachi, while Zaraki was the 11th Kenpachi. So, Kuruyashiki had been dead for many years.
"Well, enough of these unhappy topics. Let me tell you about the Hueco Mundo Expeditionary Force," Kyoraku said, snapping out of his sadness.
"About the Hueco Mundo Expeditionary Force..."
…
Three days later, Sokyoku Hill.
Everyone going to Hueco Mundo to support the Hueco Mundo Expeditionary Force had gathered here. Captains and most Shinigami of the Gotei 13 had come to see them off.
Thus, even though Sokyoku Hill was spacious, it was nearly packed.
"Toshiro, once the issues with the expeditionary force are largely resolved, you can return. However, during this time, you must ensure your safety," Yamamoto instructed.
Although Toshiro was serving as commander of the expeditionary force this time, he wouldn't be stationed in Hueco Mundo permanently.
Once the problems facing the expeditionary force were solved and the situation in Hueco Mundo stabilized, he could return. Otherwise, if he had to stay there indefinitely, no way would he have agreed to go.
Momo and Toshiro's friends, like Renji, Kira, and even Rukia, had all come to see him off.
Even though Rukia knew she'd run into Renji, she still came.