According to Unohana's Kaidō theory, Kaidō worked by using reishi to repair spirit bodies. But he wasn't a spirit body. When he learned the principle, he thought this technique would be useless to him.
But Unohana healed him anyway, making him reconsider the difference between flesh and high-density spirit bodies.
If he used some basic science from his previous life, maybe Reishi was just another kind of molecule or atom. Or perhaps the camouflage of Endspace was so advanced that he could survive temporarily as a spirit body in this world.
Next, each student was given a white mouse to practice Kaidō.
After all, not everyone could use Kaidō successfully, and if everyone practiced on themselves, Unohana would have to heal most of them.
Gusion made a small cut on his mouse and tried to recall the feeling when Unohana treated him.
As expected, Kaidō wasn't easy. He failed the first time.
It took over a dozen tries before he managed to control the reishi to heal the mouse's wound.
After a while, the mouse's wound healed, but a clear scar remained.
His Kaidō was still far inferior to Unohana's—slower and less effective.
"You need to imagine its original, uninjured state and guide the reishi to restore it."
Unohana's voice sounded beside him. At some point, she had come to his side.
Looking at Gusion's mouse, Unohana was a little surprised. She had substituted many times but had never seen anyone succeed with Kaidō in their first class.
By the academy's standards, Gusion could already pass Kaidō. With more practice, he'd qualify to join the Fourth Division as a healer.
This young man… does he have no weaknesses?
She'd heard that Gusion had already stumped the kendo and hakuda teachers—privately, those teachers admitted they simply couldn't teach him. Not that he was a troublemaker, just that they truly couldn't teach him.
Unohana could only be glad her Kaidō was top-notch—at least in this field, she could still teach him.
Under her guidance, Gusion cut the mouse again and tried Kaidō as she instructed.
This time, the wound healed much faster, and the scar was barely visible.
Unohana's eyes lit up, and she leaned in closer, staring at Gusion. "Tell me, why do you want to learn Kaidō?"
Gusion, still savoring the details of Kaidō, blurted out, "Of course, to better enjoy fighting!"
As soon as he spoke, he felt Unohana's aura envelop him. Her eyes sparkled with excitement.
Gusion realized he'd said the wrong thing—he shouldn't have spoken his true thoughts.
He almost forgot Unohana was also a battle maniac. She only stepped down as Eleventh Division Captain after meeting Kenpachi Zaraki, moving to the Fourth Division as support.
But her desire for battle hadn't lessened, just hidden well.
Before joining the Gotei 13, Unohana was considered the most notorious villain in Soul Society's history. Only after the Head Captain recruited her did she restrain herself. Her gentle demeanor now was just a mask.
"I see… Stay after class."
Unohana quickly hid her excitement, her face returning to its usual gentle smile, eyes narrowed. "Since you like Kaidō so much, I'll give you special guidance."
A chill ran down Gusion's back, but he knew that Unohana teaching him Kaidō one-on-one was a rare chance. He had no reason to refuse.
Since you want a sparring partner, surely you won't kill me while teaching Kaidō, right?
Now that he thought about it, he wondered where Kenpachi Zaraki was.
He'd asked Aizen, who said the current Eleventh Division Captain was Kuryashiki Kenpachi, and no one named Zaraki was in the academy.
As he pondered, the bell rang. Most students left disappointed, having failed to heal their mice.
Gusion didn't have to worry about the next class—he only had one elective today.
When the last student left, a faint breeze from spiritual pressure closed the door.
What made Gusion uneasy was that he thought he heard the door being locked.
He looked up at Unohana, who still wore her pale cherry-gray haori. She smiled at him, her delicate hand resting on her sword hilt.
"Gusion-kun, it's just the two of us now~"
Unohana gripped her zanpakutō Minazuki and slowly drew it, inch by inch, under Gusion's confused gaze.
"Unohana-sensei?"
Gusion's danger radar was blaring. "What are you…?"
Unohana smiled gently, like a big sister next door. "Of course, I'm letting you experience advanced Kaidō."
Gusion was just about to protest when, in the next instant, he saw a fountain of blood shoot up, staining the ceiling.
His dark eyes, under the light and blood, reflected a tinge of red. The delayed pain let him realize what had just happened, and after the pain came a surge of excitement.
He wasn't a masochist, but he'd never seen a blade so fast. Even his dynamic vision couldn't catch it. The blow was so quick that his senses didn't even warn him.
The cut ran diagonally from his left shoulder, slashing through flesh, bone, and heart. His still-beating heart struggled in vain to keep his body alive but only made the blood fountain higher.
As his body functions faded, Gusion slowly collapsed, but before he hit the floor, a gentle hand caught him.
Through his still-clear vision, Gusion saw Unohana's warm, sisterly smile. "I'll teach you with your body."
Gusion nodded slightly. Even on the verge of death, he stayed calm. He now knew what Unohana was doing—she wanted him to personally experience how advanced Kaidō healed near-fatal wounds.
So he focused, preparing to observe her technique.
Unohana's hand glowed pale blue again, brighter and wider than before.
Strangely, even while dying, Gusion's mind was clearer than ever, and his senses sharper.
Even with his eyes closed, he could feel the fine details of Unohana's Kaidō, like countless silk threads brushing his chest.