That same night, Shin shared part of the reward he'd received from Isane with her.
Isane noticed the change instantly—the surge in her own spiritual pressure was impossible to miss. Startled, she turned to Shin, only for him to explain that it was an ability of his Zanpakutō: it allowed him to permanently share his own reiatsu with others.
"An ability like that…?!" Isane was floored. "How is that even possible?!"
"How do you feel? How much has your reiatsu increased?" Shin asked.
Though his own spiritual pressure now ranked at the level of a Third-Class Reiatsu (well within captain-level standards), the reward he'd received through his bond with Isane wasn't massive. Even then, he only passed on a tenth of it to her—hardly a lot.
And beyond raw reiatsu, there was another change: a shift in her Zanpakutō resonance.
Despite being Squad 4's vice-captain, Isane had never come close to unlocking Bankai.
Her expression flickered with conflict. Then she turned to Shin and said quietly, "Shin… can you take it back?"
"What? Why?" he blinked.
She exhaled, firm but gentle: "This is power you earned. How can you just give it away? Shin, your talent is incredible. Your future will be—is—legendary. You can't afford to waste your strength on me."
Shin chuckled. "I'm not lacking in reiatsu."
Isane shook her head. "That's not the point. Growth in spiritual pressure is meant to be earned over time—"
Shin interrupted. "I've only been a Shinigami for what, a year? And I'm already ranked at third-class spiritual power. And you?"
Isane faltered, silent for a moment. "…I can't compare to your talent."
Shin tucked a strand of hair behind her ear. "Then why separate what's mine and yours? If we're together… my talent is yours. No matter where I end up, I want you by my side."
"But…" she faltered again, voice trailing to a whisper.
"It's fine. I already told you—I'm not losing anything by giving you this. My Zanpakutō still isn't fully understood anyway, so I can't give too much yet."
"…Okay."
She said nothing more, only hugging him tighter.
[Affection: 93]
By day, even on off-days, Shin rarely left home. There wasn't much entertainment in Soul Society. For him, better to stay in and study his Zanpakutō.
"Stasis"—one of his Shikai abilities—he mostly used on himself, rendering his body immune to external harm.
It also let him conceal his Zanpakutō's true form, making others perceive him as still unarmed or unreleased.
During the Inter-Squad Exchange Tournament, he'd once applied "Stasis" to Seirō, which demonstrated that when used on others or external objects, the energy cost grew significantly.
"Rewind", on the other hand, was primarily a healing ability.
Shin had long wanted to test its limits, but his own reiatsu pool remained the bottleneck.
"Rewind" consumed reiryoku based on the target's spiritual density and the time gap being reversed.
Ordinary Shinigami were easy to heal—they had low-density spiritual bodies. But healing Zaraki Kenpachi had drained nearly half of Shin's reserves.
Though part of that was due to the severity of Zaraki's injuries, the conclusion remained: "Rewind" scaled with two variables—the reiryoku gap and the time distance reversed.
Between his two core abilities, "Rewind" burned far more energy than "Stasis."
Though Shin's Third-Class spiritual power placed him among the top-tier fighters in Soul Society, he still couldn't define the true limit of "Rewind."
It was possible… perhaps it had no limit, so long as his reiatsu remained strong enough.
Deep in thought, Shin was snapped back to the present by a sudden sound:
"Meow."
He stiffened instantly.
There—on the edge of his bed—lay a black cat. Sleek, silent. Its golden eyes locked with his. Its front paws were crossed, tail flicking lazily.
It was the same cat from Shiba Kaien's wedding.
He couldn't sense any spiritual pressure from it—none. It seemed entirely mundane.
So when had it even gotten here? How long had it been there?
He realized, a bit annoyed, that he'd grown too reliant on reiatsu-based sensing.
But that wasn't a fault, not in the Gotei. All Shinigami used spiritual thread detection for recon and perception. It was natural. But if something masked its spiritual presence… he was left blind.
Like the cloaked assailant during his field training in the human world.
Or like this cat.
He stared into its golden eyes, wondering: What are you here for?
Neither moved.
Then, with a sigh, Shin got up and headed to the kitchen. When he returned, he held a dish with half a cooked fish.
He placed it on the short table in the sitting room.
The cat stretched, walked over like it owned the place, and—unbothered—leapt onto the table to eat.
"You're not a normal cat, are you?" Shin asked.
The cat ignored him.
He reached out to pet it—its fur bristled in warning. But it didn't run. When he pulled back, it continued eating.
"You little brat," Shin muttered, amused. "You eat my food but won't let me pet you."
The fish vanished quickly. The cat licked its paws, clearly still hungry.
Shin poured it a glass of water, but the cup was too narrow for the cat's face. It sipped twice, then meowed at him—clearly annoyed.
He replaced the glass with a bowl.
"What's your name?" he asked.
The cat didn't answer. Just kept lapping the water.
Shin tried to pet it again—this time it batted his hand with a paw. Not claws. Just a warning.
He tried again—this time determined to win—but the cat moved faster than he expected. One flick and it vanished from the table, reappearing at the window sill.
Shin's eyes brightened.
That movement—that speed.
No ordinary cat could move like that.
"You leaving?" he asked with a smile. "Come by more often."
The black cat gave him one last calm look, then leapt from the sill and vanished.
Days passed.
The cat never returned.
Shin was… a little disappointed. But life in Seireitei remained quiet.
With Kaien now officially promoted to Squad 3's captain, no major events had occurred in Soul Society.
People gossiped about minor things over tea—but no one brought up the duel between Tachikawa Shin and Kenpachi Zaraki.
Only three people had witnessed it. And Zaraki himself never mentioned the loss. When Squad 11 members tried to pry, Ikkaku shut them down every time.
Seireitei remained peaceful. Pale buildings and clean streets—yet the calm felt… artificial. As if something stirred beneath it all.
Isane came to stay with Shin from time to time, but never officially moved in. Her excuse? Leaving her younger sister Kiyone alone at home made her feel guilty.
When Shin tried to set up some personal items for her, she refused. Their relationship wasn't public, and she worried about someone noticing.
Shin didn't complain. He simply gave her more affection at night.
Life settled into a rhythm—missions, tending to Squad 4's patients, occasional evenings with Isane.
He continued his monthly inter-squad duels, challenging each division in turn—Squad 5 and Squad 9 included.
Neither Aizen nor Tōsen ever showed up. They always sent their lieutenants or third seats.
With a permanent home now, even Hisagi visited from time to time—though when he asked to move in, Shin immediately refused.
Hisagi was still just a regular seated officer. Not qualified for private quarters.
Kiyone didn't visit much. Last time, she only came because Shin had gone to fetch her himself.
Over a month later—
Shin saw it again.
That black cat.
Laid across his window sill, lazy, tail twitching in rhythm.
"It's been a while," he greeted, smiling as he walked into the kitchen.
He returned with a whole fish this time.
The cat jumped down, landed on the table, and began eating as if nothing had changed.
Shin watched it closely.
Then asked, calmly—
"…You're a Shinigami, aren't you?"