Susukawa didn't dare to gamble.
You'd have to be insane to—his teacher was a Kuchiki, the noble house that stood at the very top of the Four Great Families. Expelling a second-year like him would only take a word.
After the boy shuffled out of the classroom, the teacher scanned the room and finally stopped at the student sitting in the back by the window.
"Ichirō, didn't you use to fight tooth and nail just to get that second-to-last seat? Well, here's your chance. She'll be sitting behind you. Make her a desk and chair."
"…" Ichirō sighed helplessly. "Seriously? Has the Academy gone bankrupt? We can't even afford spare furniture now?"
"She was just reassigned to our class. Quit yapping, or I'll have her take your seat instead. I still have a lecture to start."
"All right, all right—fine, fine! I'll do it. Hard to get a chance to show off in my homeland again, anyway."
With a reluctant wave of his hand, a faint light flickered from his sleeve.
In an instant, a complete set of desk and chair materialized out of thin air, drawing wide-eyed amazement from Suzuran Tsukiyo behind him.
"Not bad," the teacher said, nodding in approval. "Now then, let's begin. Today's lesson—the political structure of the Soul Society at the time of its founding…"
....
Suzuran sat down behind Ichirō, her bright eyes full of curiosity as she studied the freshly created furniture. This was the first time she had ever seen such a technique.
When class ended, Ichirō was still buried in his notes until Urahara tapped his shoulder.
"What's up?" Ichirō asked, only to notice Yoruichi and Urahara chatting with Suzuran. He shrugged, closed his notebook, and turned around to join in.
"Your Zanpakutō is so beautiful," Urahara said brightly. "What's its ability?"
Shff— The sound of writing filled the air.
Mine is a healing-type Zanpakutō. It can absorb injuries and convert my spiritual energy into life force for recovery.
"Whoa, that's pretty good," Ichirō remarked. "If you practiced that alongside the old-style Kaidō, your efficiency would skyrocket."
"The old-style Kaidō?" Urahara blinked. "Wait, are there going to be changes to Kaidō?"
"Huh? Didn't I tell you?" Ichirō tilted his head. "Lately the Captain and I have been researching a classification system for Kaidō—giving each spell a number and incantation, like Hadō and Bakudō."
"…"
A stunned silence fell across the group.
"You and the Captain are researching this? Together?" Urahara's jaw dropped.
"…What? You don't think I'm qualified?"
"I mean—your Kidō level is only around number forty, right? You can handle something that advanced?" Urahara asked skeptically. The news was just too shocking.
"First," Ichirō said dryly, "I study the principles of Kidō and the techniques behind it. The numbering doesn't really matter. And second—it's not forty anymore. I'm up to forty-five. There are barely a dozen left in the Academy that I haven't mastered."
"…Monster." came the collective thought.
"So what's this reform about, exactly?" Yoruichi asked.
"Oh, that? It started last week during the Captain's special lecture—"
---
One Week Earlier
Originally, there hadn't even been a class scheduled.
Two fresh recruits from the Eleventh Division started a brawl inside the Fourth Division's barracks, injuring several nurses in the process. Unfortunately for them, Captain Unohana happened to witness it.
And so—lucky them—a special Kaidō demonstration began.
The subjects: the two Eleventh Division idiots.
Under Unohana's calm, smiling gaze, the two trembling men were immobilized. She sealed away their pain receptors with spiritual energy and began to lecture while methodically snapping their limbs one by one.
Every crack of bone made the students flinch, but soon their horror gave way to fascination. The Captain's technique was so precise, her explanation so clear, that everyone found themselves engrossed in the lesson—completely ignoring the two screaming soldiers being repeatedly broken and healed.
Well… everyone except Ichirō.
His background in Body Transmutation made him see something different. Though their limbs were continuously shattered and restored, Unohana's control ensured no permanent damage. Instead, the process purged old internal injuries, reforging the body like tempered steel.
It was disturbing—but undeniably effective.
In the long run, those two men might actually benefit from it.
If you ignored the permanent psychological trauma, of course.
Still, Ichirō had to admit—it was a two-for-one learning opportunity. A bargain, really.
Eventually, when their usefulness had run out, the trembling soldiers were set aside, and the Captain moved on to treating other patients.
At first, Ichirō watched in admiration; these subtle manipulations were a matter of experience, not talent. But the longer he observed, the more his brow furrowed.
A long-standing question was finally taking shape.
Every injury—regardless of type—was treated in the exact same way.
That couldn't be efficient.
---
Captain Unohana had been watching Ichirō the entire time. She was quite fond of the brilliant young student and noticed his expression change.
She paused her work.
"Ichirō, do you have a question? Go ahead."
He nodded. "Captain, why isn't Kaidō categorized? Every wound is treated with the same Kaidō, yet the hand movements differ depending on the injury. Shouldn't Kaidō itself be revised and classified?"
"Like Hadō and Bakudō?" she asked.
"Exactly. I've studied their incantations—they're essentially ritual formulas that resonate with the world itself. Early Kidō was split between chantless and chanted forms, with vast differences in power. Over time, the two developed into the modern structured system."
"I understand what you mean," Unohana said softly, "but this is different. We can no longer perceive new incantation texts. Both the Fourth and Twelfth Divisions have been researching this for years. I'm glad you've realized the problem—but unfortunately, that path is a dead end." She sighed.
(Unable to perceive new incantations… could that be because of the Soul King?)
Ichirō's eyes flickered with intrigue. That was a valuable clue.
"No, Captain," he said after a pause. "That conclusion might not be absolute. Even if we can't sense new incantations, we can still work with the existing ones."
"Oh?" She raised an eyebrow. "Existing incantations?"
"Yes. I analyzed every incantation under number sixty in the Academy archives. I found sets of phrases that differ in wording but perform similar functions. When isolated, these terms slightly enhance all Kidō. Some even carry unique resonance effects—"
"That's enough for now."
Unohana gently interrupted, her smile returning. "Class dismissed. We'll continue this next week. Ichirō—come with me."
Before he could finish, she ended the lecture early and led him toward the depths of the Fourth Division's barracks, her eyes gleaming with interest.