That night, Nobu passed part of the reward he had gained from Isane back to her through Feedback.
Isane felt the shift in her own spiritual pressure almost immediately.
While she was still reeling in surprise, Nobu told her it was his Zanpakutō's ability—to permanently share a portion of his reiatsu with another.
Her eyes widened. "How can such an ability even exist?!"
"How does it feel? How much has your reiatsu risen?" he asked.
At his current level, he was already at the standard of Third-Class Reiatsu, but what he had gained from her was not that much to begin with. Sharing out even a tenth of that was… limited.
And it wasn't only reiatsu—there was also Zanpakutō unlock progress.
Kotetsu Isane, despite being the vice-captain of the Fourth Division, had still never touched the threshold of bankai.
Her expression shifted for a long while before she suddenly said, "Nobu… can you take this power back?"
"What's wrong?" he asked in puzzlement.
She exhaled slowly. "This is something you trained for—how can you just give it to me? Your talent is incredible; your future achievements will be amazing. Don't hold yourself back for something like this."
Nobu couldn't help but laugh. "I'm not short on reiatsu."
Isane shook her head. "Even so, reiatsu growth comes from years of accumulation—"
He cut her off. "How long have I been a Shinigami? And I'm already at Third-Class Reiatsu. What about you?"
She fell silent for a moment. "…Of course I can't compare with your talent."
Nobu brushed the hair away from her ear, his tone warm.
"Do we really need to keep score like this between us? My talent is yours too. No matter how far I go, I want you standing at my side."
Her voice dropped to almost nothing. "But…"
"Enough. I've told you—I'm not short on what I'm giving you. My Zanpakutō's full scope isn't even clear to me yet, so what I can give now isn't much."
"…Alright."
She said no more, only held him tighter.
[Affection: 93]
...
By day.
Even on rest days, Nobu rarely left his home.
The Soul Society offered little in the way of leisure.
Better to stay home and study his Zanpakutō.
He used Stagnation mainly on himself, rendering him immune to outside harm—and to mask the blade's true form, fixing its appearance in others' eyes as the unassuming state before he ever carried Shigan Higan.
At the Exchange Meet, he had even used Stagnation on Aoshika once.
Applied to objects or others, the energy cost spiked sharply.
Regression, he used almost exclusively for healing others.
He had long wanted to test Regression's limits, but the constraint was always reiatsu.
Its cost was tied directly to the target's reishi density.
Ordinary Shinigami were easy enough—their low spiritual pressure meant negligible drain.
But healing Zaraki Kenpachi had taken half his strength in one go—partly because Kenpachi's injuries were so severe.
From this, Nobu could conclude: Regression consumed reiatsu in two ways—first, the difference in reishi density between the target's current state and the restored state,
and second, the temporal distance being rolled back.
Compared in pure drain, Regression cost far more "blue" than Stagnation.
At Third-Class Reiatsu, his spiritual pressure was already captain-class, one of the highest in Seireitei.
Even so, he still couldn't push Regression to its limit.
Perhaps, if the reiatsu were great enough… there was no limit.
He was deep in thought when a sharp meow snapped him alert.
On the edge of his bed lay a sleek black cat, front paws crossed, tail swaying lazily,
gold eyes fixed on him.
The same cat he had seen at Shiba Kaien's wedding.
There wasn't the faintest trace of reiatsu to be felt from it—utterly like an ordinary cat.
He hadn't noticed when it arrived or how long it had been there.
I'm getting too used to relying only on reiatsu sensing…
It wasn't wrong—tracking reiraku to sense and scout was a standard Shinigami skill.
But anything that masked its presence left him blind—like the cloak worn by the attacker during his Shin'ō Academy internship in the Living World.
Or… this black cat.
He met its gaze, wondering why it had come.
Man and cat watched each other without moving.
After a while, Nobu rose and went to the kitchen.
When he came back, he carried a plate with half a fish.
He set it down on the low table.
The cat rose, jumped into the room without a hint of fear, then onto the table, and began eating right in front of him.
"You're not just some normal cat, are you?" he asked.
The cat ignored him, intent on its meal.
He reached out to pet it—it fluffed up in warning, but didn't flee, and once he withdrew his hand, resumed eating.
"You…" He almost laughed. "Eat my food but won't let me touch you."
Half the fish vanished quickly.
It sat licking its paws, clearly wanting more.
Nobu poured it a cup of water, but with the narrow rim, it couldn't get its face in, two sips and it meowed at him in protest.
When he poured water into a bowl instead, he asked, "What's your name?"
The cat didn't respond, just lapped steadily at the surface.
He tried to pet it again—this time it batted his hand away.
Nobu, unwilling to let it win, made a grab for it, but its speed shocked him.
In a blink, it was gone from the table and standing on the windowsill.
"As I thought…" His eyes lit.
That speed—he'd almost missed it entirely.
No normal cat could do that.
"Heading out? Come by often."
He smiled.
The cat gave him one calm look,
then leapt from the window and was gone.
...
In the days after, Nobu never saw it again.
He felt a twinge of disappointment, and life slid back into quiet.
Since Kaien had taken over the Third Division, nothing significant had happened in the Soul Society.
Only the sort of trifles fit for idle gossip—and as for the Fourth Division's Third Seat sparring with Zaraki-taichō, that never spread.
Only three had witnessed it, and Ikkaku saw no reason to advertise his captain's loss.
When asked, he simply waved off his own division's curiosity.
Seireitei remained as still as ever.
The pale white buildings showed no hint of the undercurrents beneath.
Isane still stayed over sometimes, but never moved in.
She said with only her sister at home, Kiyone would be too lonely if she left.
Nobu had wanted to keep some of her things at his place, but she refused. Their relationship wasn't public, and she feared visitors might notice.
He could only accept it, and treat her all the more gently at night.
Life passed in calm routine: leading teams on missions, working in the General Treatment Ward, the occasional overnight with Isane.
He also kept up private sparring with other divisions, including the Fifth and Ninth.
Aizen and Tōsen never refused, but left arrangements to their lieutenants or third seats.
Now that he had a fixed home, Shūhei would drop by often—once even suggesting moving in,
only for Nobu to refuse without hesitation. Shūhei was still only a regular unseated officer, no right to independent housing.
Kanisawa came by far less, and last time had only come because Nobu had called him out.
...
Over a month later.
Nobu saw the black cat again, lounging on his windowsill, tail swaying lazily as before.
"Long time no see," he greeted it, heading to the kitchen to fetch a whole fish this time.
The cat leapt to the table and began eating before him.
Watching it, Nobu suddenly said,
"You're a Shinigami, aren't you?"