1st Division.
"Lieutenant Kotetsu, what brings you here?" Yamamoto asked, looking at Isane before him.
After leaving the 4th Division, Isane was no longer affected by Hyorinmaru and returned to normal.
"Yes, Captain-Commander. Captain Unohana sent me to inform you that Toshiro has begun Bankai Training," Isane replied respectfully.
"Is that so? He's already started Bankai Training. It seems his battle with Kenpachi was quite fruitful. I wonder how long it will take him to master Bankai," Yamamoto mused.
"You may return. Report to me immediately once Hitsugaya Toshiro has mastered Bankai," Yamamoto instructed.
"Um..." Isane hesitated.
"What is it?" Yamamoto frowned.
"No, it's nothing," Isane said quickly.
With that, she hurried out.
Seeing Yamamoto frown, the timid Isane didn't dare mention that Unohana had told her to stay at the 1st Division temporarily.
'What to do now? Well, I'll go stay with my sister for a while.'
With nowhere else to go, Isane decided to spend some time with her younger sister.
'Hitsugaya Toshiro, please master Bankai quickly so I can go back,' Isane prayed internally.
4th Division, Underground Storage.
Toshiro, fighting Hyorinmaru, was completely unaware that his actions had caused Isane to be unable to return.
Clang clang clang!
The sounds of clashing swords echoed continuously throughout the underground storage.
Neither Toshiro nor Hyorinmaru used their Zanpakuto's special abilities. For them, whatever one could do, the other could too. Exchanging skills in a barrage wasn't very meaningful.
So, they simply attacked each other using Zanjutsu and Hakuda.
At first, Toshiro could only barely hold out for a while before being defeated.
But Toshiro didn't give up. He chose to fight on despite repeated losses.
Finally, Toshiro's monstrous talent began to manifest. He continuously memorized and analyzed Hyorinmaru's every move, mastering them and then using them against her.
Thus, Toshiro's swordsmanship and combat experience skyrocketed. Hyorinmaru found it increasingly difficult to suppress him.
Clatter!
Finally, the sword in Hyorinmaru's hand was knocked away by Toshiro, and Toshiro's Zanpakuto pointed at a vital spot on Hyorinmaru.
And this had taken less than a day!
"Congratulations, Toshiro. That was faster than I expected," Hyorinmaru said, appearing pleased despite her defeat.
"Thank you, Hyorinmaru," Toshiro said, withdrawing his Zanpakuto.
Toshiro could sense that during the earlier battles, Hyorinmaru hadn't seriously tried to injure him and had even deliberately guided him.
Otherwise, he wouldn't have been able to keep fighting after so many defeats, nor would he have progressed so rapidly.
"No need for thanks. It's all what I should do, and what I willingly chose to do," Hyorinmaru said, shaking her head.
"Now, Toshiro, accept my power."
Hyorinmaru opened her arms and walked towards Toshiro, then embraced him.
"Hey, Hyorinmaru, what are you doing..."
Before Toshiro could finish, Hyorinmaru dissolved into streams of blue light, merging into Toshiro's body.
Then, Toshiro felt the Reiatsu within him begin to surge violently.
Crack!
For a moment, Toshiro felt as if he heard the sound of an internal blockade shattering.
His previously stagnant Reiatsu began to rise rapidly.
Boom!
A whirlwind of Reiatsu swept through the underground space.
Toshiro's Reiatsu swiftly broke through the Lieutenant-level limit, reaching the early Captain-level, but it still didn't stop.
Crack!
Toshiro broke through another bottleneck. His Reiatsu rose to the mid Captain-level before gradually stabilizing.
'This feeling is really great.'
Toshiro closed his eyes, savoring the sensation of being filled with power.
When Toshiro opened his eyes again, the mid Captain-level Reiatsu within him had been sealed. He would need to release Bankai to unlock it again.
Simultaneously, the name of his Bankai appeared in his mind once more.
Daiguren Hyorinmaru.
Still the same name.
Next, Toshiro didn't continue studying his Bankai's power but headed outside.
At the entrance to the underground space, Unohana and Momo were waiting.
Momo had woken up not long after Toshiro began his Bankai Training and had been waiting here ever since, staying up for nearly a full day and night.
"Momo-kun, don't you want to rest?" Unohana asked, looking at Momo, who seemed about to fall asleep.
"No, I want to wait here for Toshiro," Momo said, rubbing her eyes.
"But we don't know how long it will take Toshiro-kun to emerge. Can your body hold up?" Unohana said with concern.
"It's fine. Didn't you say that with Toshiro's talent, he'd probably complete his Bankai Training in about two days? Just two days without sleep, I can manage," Momo said, yawning.
Creak!
Suddenly, the door to the underground storage opened.
"Idiot. Even if you stay here, you can't train for me," Toshiro said as he walked out.
"Toshiro, did you complete your Bankai Training?" Momo asked, walking up to him excitedly.
"Yeah, finally done," Toshiro nodded.
"Ara ara, our genius Toshiro-kun, you really love being unpredictable. I thought you'd need at least two days, yet you finished in less than one," Unohana teased.
Although Unohana had considered the possibility of Toshiro taking only one day, the thought had been fleeting.
The current time was morning, while Toshiro had started training at noon. That meant less than a day had passed.