For Toshiro, Yamamoto held great expectations, even listing him alongside Kyoraku as candidates for the next Captain-Commander.
Between the two, Yamamoto actually favored Toshiro more. After all, compared to Kyoraku's laziness, Toshiro was diligent, conscientious, and managed the 10th Division meticulously. Moreover, Toshiro's talent surpassed Kyoraku's.
Thus, after Toshiro's breakthrough, Yamamoto had decided Toshiro would be the next Captain-Commander, succeeding him in protecting the Soul Society.
However, before that, Yamamoto wanted to personally test Toshiro's strength. Although Toshiro's imposing might during his breakthrough suggested his strength might not be much weaker, Yamamoto wished to see for himself.
Having protected the Soul Society for so long, Yamamoto's emotional attachment ran deep and no one could match it.
Therefore, without personally testing Toshiro's strength, Yamamoto couldn't rest easy entrusting the Soul Society to him.
As for Toshiro, hearing Yamamoto wanted to fight him was sudden and unexpected. Yamamoto was the Gotei 13 Captain-Commander, the strongest Shinigami in a thousand years. His prestige had suppressed the Soul Society for over a millennium, defeating countless powerful enemies… the pillar of the entire Soul Society.
Having lived in the Soul Society for so long, Toshiro understood what the name Yamamoto Genryusai Shigekuni meant.
Although in the original work, Yamamoto was defeated by Aizen and Yhwach, ending up with nothing left, giving an impression of not being overwhelmingly strong, underestimating his strength based on that would be a grave mistake.
Both Aizen and Yhwach, when fighting Yamamoto, avoided direct confrontation, resorting to schemes.
If he were to fight Yamamoto, even after his breakthrough and reaching the same level, Toshiro still lacked confidence in victory.
"What's wrong, Toshiro? Are you afraid?!" Seeing Toshiro's hesitation upon hearing about the fight, Yamamoto sharply shouted.
Hearing Yamamoto's challenge, Toshiro instantly snapped out of it.
'Hah, when did I become hesitant in the face of a challenge?' Toshiro inwardly mocked himself.
"Alright then, Genryusai-sensei! I accept your challenge!!" Toshiro declared loudly.
Seeing Toshiro agree, Yamamoto said satisfied, "Good. Worthy of being my chosen successor."
Yamamoto knew Toshiro had just broken through and hadn't fully mastered his new power. Fighting an ancient being like himself, Toshiro's chances weren't high. But if Toshiro lacked the courage to fight, Yamamoto would have been disappointed.
"In that case, return first. You just broke through and likely haven't familiarized yourself with your new power. I'll give you one month. Within this month, strive to familiarize yourself with your post-breakthrough strength, then come find me," Yamamoto instructed.
"Yes, Genryusai-sensei," Toshiro said gravely.
With that, Toshiro left.
…
10th Division, Captain's Office.
"Yo, Captain, you're back," Rangiku lounged on the sofa, leisurely drinking tea.
"Oh, right, Captain, was that earlier Reiatsu yours?" she asked.
"Yeah, it was," Toshiro replied, sitting on the sofa opposite her and pouring himself some tea.
Hearing this, Rangiku grumbled, "Honestly, Captain, what were you thinking, releasing Reiatsu like that in broad daylight? I was eating earlier when that massive pressure hit. In the panic, I almost choked to death!"
"But, speaking of which, I never realized your Reiatsu was so powerful. Under its pressure, I could hardly breathe!" Rangiku patted her chest, still shaken.
"Well, it wasn't this strong before. I just happened to break through," Toshiro explained casually.
Then, Toshiro sat up straight, expression serious. "Rangiku, I have an important task for you."
"Huh?" Seeing Toshiro's sudden solemnity, Rangiku somehow felt a sense of panic. Moreover, Toshiro affectionately called her 'Rangiku'… this felt even more ominous. Rangiku knew well that Toshiro usually called her by her surname, 'Matsumoto', to appear more mature and dignified. This sudden affection surely meant no good.
Sure enough, Toshiro continued, "Rangiku, I have a very important matter recently and need to take a month's leave. So, during this month, division work is entrusted to you!"
Then, he walked over, patted her shoulder, and said, "Good luck, Rangiku! I believe as an experienced Lieutenant, such a small matter won't trouble you!"
Hearing this, Rangiku's eyes darted around. Then, she suddenly clutched her stomach and cried out, "Ouch! It hurts!"
"Captain, I just remembered! Earlier, I was injured by your Reiatsu. Now it's acting up suddenly. My whole body aches terribly! Ouch... I can't take it! I need to go to the 4th Division for treatment!"
Saying this, she stood up to leave.
"Huh?" After two steps, Rangiku realized her body hadn't moved. Looking back, she saw Toshiro firmly holding her.
Toshiro said expressionlessly, "Rangiku, your acting is too exaggerated. Also, if you were injured by my Reiatsu, why is it acting up only now? Is your body's reaction too slow, or does my Reiatsu have a delayed injury effect?"
Rangiku grinned cheekily. "Ahaha... well..."
"Enough, Rangiku. Stop fooling around. I really have something important this time," Toshiro said earnestly. "In one month, I'll be fighting the Captain-Commander. Though chances of winning aren't high, I can't afford to lose too badly. So, I need this month to fully familiarize myself with and master my post-breakthrough power."
"Fighting the Captain-Commander?!" Rangiku exclaimed in shock.