Of course, with the total amount of Reiatsu unchanged, an increase in 'quality' also implies a decrease in 'quantity'.
Although it might seem the same, an increase in Reiatsu density results in a significant enhancement of attack power.
At the same time, after the Reiatsu is compressed, it occupies less volume, leaving more space within the body to accommodate Reiatsu.
Furthermore, a Shinigami's body is composed of Reishi. If the density of Reishi in the body can also be increased, then the body's strength and defensive capabilities will be greatly enhanced.
'Since compressing Reiatsu and increasing Reishi density have so many benefits, I should formulate a training plan based on these next.'
Toshiro decided to create a systematic and reasonable training plan to improve his strength as quickly as possible.
After careful consideration, Toshiro made a decision.
Morning: Compress his own Reiatsu to increase its density.
Afternoon: Compress the Reishi density of his body to improve physical strength.
Night: Train Reiatsu to increase the total amount of Reiatsu.
As for classes, he would temporarily stop attending.
He had already mostly mastered the first-year curriculum. After following his training plan for a while to see the improvement in his strength, he would skip to the second year.
As a genius, if he hadn't skipped a grade, it would be embarrassing to call himself a genius.
The known examples, Ichimaru Gin and Shiba Kaien, were both grade-skipping maniacs.
They graduated from the Shin'o Academy in just one year, skipping from first year to sixth year within that time.
Toshiro probably couldn't break that record.
Although his talent was far greater than theirs, the Shin'o Academy only holds graduation exams once a year.
Even if Toshiro were a genius and mastered six years of content in one month, he would still have to wait eleven months to take the graduation exam with everyone else, unless he could get the school to hold a graduation exam just for one person.
But at the very least, he couldn't perform worse than them.
"But first, I need to find a suitable training location." Toshiro glanced at the icy, mountain-like surroundings around him.
In the Seireitei, in a remote valley north of the Shin'o Academy.
A waterfall cascaded down, crashing fiercely onto a shallow pool, splashing up waves.
Toshiro looked at the waterfall before him and nodded in satisfaction.
Earlier, Toshiro had specifically gone to the 10th Division to ask Rangiku if there was a place in the Seireitei with a waterfall that was also secluded.
The reason for finding a place with a waterfall was that Toshiro remembered the common trope in movies, TV shows, and anime of using waterfalls for training.
So, Toshiro wondered if he could use the impact force of the waterfall to externally compress his body while he internally compressed his Reiatsu, thereby improving efficiency.
Therefore, Toshiro wanted to find a place to try it out.
"Alright, let's begin." With that, Toshiro removed his school uniform, keeping only his short jacket and pants, and walked into the waterfall.
Boom!
The waterfall fell with a thunderous force, crashing onto Toshiro's body.
Toshiro's body bent, then immediately straightened. He closed his eyes and focused his mind on compressing his Reiatsu.
A long time later, Toshiro opened his eyes, a gleam flashing within them.
'It is indeed effective. However, the effect is most pronounced for compressing the Reishi density of the body. As for compressing Reiatsu density, the effect isn't as significant as compressing bodily Reishi density, but it's still quite good.' Toshiro thought after assessing his physical condition.
After all, the compressive force of the waterfall acts directly on the body's surface, which is why it's most effective for increasing bodily Reishi density.
Since it was effective, Toshiro decided to train here.
Subsequently, Toshiro blasted a cave opening into the adjacent cliff face. During his training period, he would stay here during the day and return to his dorm at night to train Reiatsu.
"Then let's continue training." After saying this, Toshiro stepped back into the waterfall.
After training like this for several days, Toshiro returned to the Academy to apply for a skip to the second year. After passing the assessment, he attended classes for a few days before returning here to train.
Once fully immersed in his training, Toshiro felt time pass swiftly. In the blink of an eye, half a year had gone by.
During these six months, Toshiro repeated the cycle of training for a period, returning to school for classes, then applying for a grade skip. Now, Toshiro had become a sixth-year student at the Shin'o Academy.
In the valley where Toshiro trained.
"Ice Dragon Flash!" Toshiro called out softly.
A blue light shone on Hyorinmaru, and then Toshiro swung it forcefully towards a mountain peak. A blue flash streaked by.
Boom!
With a loud crash, the mountain peak was directly cut in half, followed by a 'crack' as it shattered into ice fragments.
"Hmm, this level of power has reached what it was back then." Toshiro nodded in satisfaction.
"Hado #88, Hiryu Gekizoku Shinten Raiho!" Toshiro shouted.
A pillar of blue lightning shot forth, obliterating all trees and rocks blocking its path.
The power was extremely formidable, even surpassing the normal level due to Toshiro's high Reiatsu density. However, Toshiro frowned, not satisfied.
Because the cost of this technique was too great.
After half a year of training, Toshiro's Reiatsu had reached the limit of Lieutenant-level, and its quality was several times that of others. Even so, it consumed nearly half of his Reiatsu.
Originally, this technique wasn't something someone at Lieutenant-level Shinigami could master, let alone use without incantation.
But because Toshiro's Reiatsu control far exceeded that of ordinary people, not only could he master the 88th Kido, but he could also grasp those above 90.
However, this was somewhat useless. Without sufficient Reiatsu, he still couldn't perform it.
'Forget it, I'll keep this move as one of my trump cards.' Toshiro stopped dwelling on it.
Then, Toshiro picked up a sharp stone from the ground and forcefully scratched it across his arm.
Don't misunderstand… Toshiro wasn't trying to harm himself. He was testing his body's resilience.
After Toshiro scratched his arm, only a white mark appeared, which then quickly faded.
As the Reishi density of Toshiro's body increased, his defensive capabilities and recovery rate had greatly enhanced, making it difficult for people of the same level to injure him.
'My training ends here for now. It's become very difficult to improve further by continuing.' Toshiro decided internally.
Now, Toshiro's Reiatsu, Kido, physical strength, and other aspects had all reached their current limits. To break through further, he would have to wait until he reached captain level.
"Now, I should return to school. It's been a long time since I've seen Momo… I suddenly miss her a bit." Toshiro felt he was a somewhat negligent boyfriend, having left his girlfriend alone to go train.