Over the next few days, Kanzaki Kumo continued training step by step. Although he still could not learn the first form, his proficiency with the other sword forms kept shooting up. His Total Concentration Breathing training was also progressing steadily, and his physique continued to grow stronger.
While Kanzaki Kumo trained one steady step at a time, loud disturbances occasionally came from the area around the Ubuyashiki Estate.
Over those days, the sisters Hinaki Ubuyashiki and Nichika Ubuyashiki truly had their eyes opened.
When they first met Gyomei Himejima, they only noticed that he was unusually tall and thought he must be very strong.
For a while afterward, Himejima came every day to study the Stone Breathing training manual. Aside from his eyes being prone to tears, he showed nothing particularly unusual.
That lasted until half a month later, the day after Kanzaki Kumo left for Mount Momiji. His long-malnourished body finally received enough nourishment, and his already towering frame grew even sturdier.
At the same time, this towering man began his physical training in earnest, performing a series of feats that left the sisters dumbfounded.
For example, he did squats while carrying three logs, each thicker than the two sisters put together, and even jogged with them.
Or he pushed a boulder over two meters in diameter to train his strength and endurance.
Or he sat beneath a hundred-meter waterfall, tempering his body under a terrifying impact powerful enough to instantly put an ordinary person to sleep like a baby.
In short, Gyomei Himejima spent those days training near the Ubuyashiki Estate. Any of the methods or equipment he used would have amounted to murder if applied to an ordinary person, but for Gyomei, they were only a starting point.
That day, Gyomei had just finished training and was about to continue studying the theoretical principles of Stone Breathing when he heard Kagaya Ubuyashiki arrive at the training grounds. He immediately turned and bowed.
"Master." Gyomei was deeply grateful to Kagaya Ubuyashiki. He had yet to contribute anything to the Demon Slayer Corps, yet he had already enjoyed such generous treatment for so many days.
"Gyomei, Kanzaki sent you a letter."
"Little Kumo? Amitabha. What did he say in his letter?" Gyomei was somewhat surprised by Kanzaki Kumo's unexpected letter. He had been meaning to find time to write and ask how the child he had cared for over a considerable period was doing, but the boy had written first.
Only after hearing Gyomei's response did Kagaya Ubuyashiki open the envelope in front of him and begin reading aloud.
The letter mainly said that Kanzaki Kumo's Thunder Breathing training was going smoothly. Apart from the first form, which he had yet to get a handle on, he was already proficient in the other sword forms. His Total Concentration Breathing practice was also progressing quickly, and Jigoro Kuwajima was taking very good care of him.
At the end, he also asked how Gyomei had been doing.
Kanzaki Kumo had written two letters. One was for Kagaya Ubuyashiki, consisting mainly of routine, almost formulaic pleasantries and thanks, with a "by the way" inquiry about how Kaigaku had been dealt with.
The other was for Gyomei. After all, they had lived together for several years, and Gyomei had taken good care of him. He had also more or less saved his life that night. Since he was writing letters, he naturally could not leave him out.
"Amitabha. As long as he is doing well, that is all that matters." Gyomei pressed his palms together. Learning that the child he had cared for over several years was safe and well put him in a good mood too.
As for a reply, Gyomei, who had never received a systematic education, could think of little to say beyond "All is well," which Kagaya Ubuyashiki personally wrote on his behalf. Kagaya also wrote Kanzaki Kumo a reply of his own, likewise filled with formulaic pleasantries, along with a "by the way" remark that Kaigaku had been dealt with.
Receiving the replies put one of Kanzaki Kumo's worries to rest. However, the almost copy-and-pasted formulaic pleasantries at the start of Kagaya Ubuyashiki's letter left him unsure whether to laugh or cry.
The head of the Demon Slayer Corps seemed a little childish.
On second thought, though, Kagaya Ubuyashiki was currently only a few years older than him, and a little younger than Gyomei. That personality was hardly out of place and actually made Kanzaki Kumo feel a little closer to him.
From then on, Kanzaki Kumo developed the habit of writing letters every few days.
Those addressed to Kagaya still opened with formulaic pleasantries, followed by amusing incidents or jokes.
Those addressed to Gyomei simply described how he had been doing, along with some expressions of concern and greetings.
It was not that Kanzaki Kumo did not want to share amusing things with Gyomei too, but Gyomei was too earnest and took things too seriously. He was an older brother one could rely on without worry, but not a very good friend to joke with. After all, he would take those jokes seriously.
Kagaya Ubuyashiki, on the other hand, was someone he could treat as a friend.
Gyomei's replies always consisted of things like "All is well." Kagaya's letters also retained the same formulaic opening as Kanzaki Kumo's, followed by his own thoughts on various amusing incidents. Occasionally, he would share an anecdote that did not involve the private affairs of Demon Slayer Corps members.
Time slipped by unnoticed in this way. Apart from Gyomei Himejima passing that year's Final Selection and becoming a full-fledged swordsman, nothing important happened.
After Gyomei passed the selection, however, Kagaya Ubuyashiki complained in a letter to Kanzaki Kumo that Gyomei was so large that an ordinary Nichirin Blade looked like a chopstick in his hand. Even Gyomei had made the rare complaint that the weapon did not suit him.
According to Kagaya, that was the first time he had ever heard Gyomei sound dissatisfied.
After considering various factors and taking Gyomei's own opinion into account, they finally decided to forge a broad axe and a spiked flail for him, with the flail's chain connected to the axe handle.
That way, the flail could deliver ferocious attacks at medium and long range, while the axe could effectively deal with enemies up close.
Kanzaki Kumo, however, asked whether any demon could really get close to Gyomei.
Judging from his memories of his previous life, even among the Upper Ranks of the Twelve Kizuki, few could manage it. Those capable of doing so probably would not willingly attempt something so strenuous and unrewarding.
After Gyomei Himejima became an official member of the Demon Slayer Corps, his correspondence with Kanzaki Kumo became much less frequent. After all, Gyomei was very powerful, and he was assigned correspondingly more missions.
Although he received corresponding preferential treatment in both pay and promotion, he had far less free time and had to travel all over the place, making correspondence quite inconvenient.
From then on, Kanzaki Kumo's letters to Gyomei went from one every few days to roughly one a month. His letters to Kagaya Ubuyashiki, on the other hand, continued at their original frequency until Kuwajima could no longer stand him writing so often and disturbing the master's work. Only then did he reduce them to once a week.
Just like that, winter arrived in the blink of an eye, and Kanzaki Kumo began preparing for the first solo journey of his life.
Kanzaki Kumo: "Seriously, it's really not that far..."
Jigoro Kuwajima: "You'll be spending the night away, and you call that not far? How much farther do you want to go, you little brat?!"
He was going to pay his respects at Kanzaki Keizan's grave.
After Kanzaki Keizan died, Kanzaki Kumo had spent quite a bit of money hiring people to help bury him. The grave was on the outskirts of that town, not far from the temple that had taken him in, close enough for a round trip in a day.
From Mount Momiji, however, even a horse-drawn carriage would take two days. The entire round trip would require at least three nights away. Fortunately, there were villages along the way, so he would not have to sleep out in the wilderness.
"Thunder Breathing, first form, Thunderclap and Flash!"
"Second form, Rice Spirit!"
"..."
"Sixth form, Rumble and Flash!"
The day before his departure, Kanzaki Kumo practiced all the Thunder Breathing techniques in the courtyard.
Indeed, after more than half a year, Kanzaki Kumo had already fully mastered every Thunder Breathing technique. The first form, which came last, had finally clicked during the days when Gyomei Himejima was taking the Final Selection.
With the first form complementing them, the other sword forms he had already mastered could unleash their power more effectively, and his transitions between techniques became more fluid.
The only thing Kanzaki Kumo found somewhat regrettable was that the lightning surrounding Kuwajima during his demonstration really was just a visual effect. The actual damage from every sword technique still came from the Nichirin Blade in his hand, or at most from the sword energy he sent slashing outward, though that usually did not travel very far either.
Whether it was the lightning of Thunder Breathing or the various effects of other Breathing Styles, they were merely dazzling visual effects produced when a special Breathing Style caused the surrounding air to resonate, combined with the movements of a Nichirin Blade.
As for why mere resonance caused by breathing could create such effects? Don't ask. If you did, the answer was that every world had its own laws. Demons existed here, so what was wrong with fights having a few special effects?
Jigoro Kuwajima sat by the door, watching Kanzaki Kumo's fluid movements and the lightning scattering freely around him, his eyes filled with pride.
Aside from his lack of actual combat experience, Kanzaki Kumo was already stronger than quite a few full-fledged members of the Demon Slayer Corps.
Still, Kuwajima was somewhat worried about Kanzaki Kumo traveling far away on his own this time. He worried not only about him encountering danger, but also about him being swindled. After all, in his eyes, Kanzaki Kumo was merely a child with a great gift for swordsmanship.
But Kanzaki Kumo was going to pay his respects to the old man who had once taken him in, so Kuwajima could hardly stop him. Yet the little brat was utterly adamant about not letting him come along.
The more Kuwajima thought about it, the angrier he got. So what if he had a bad leg? It was not as though he could not walk.
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