Bleach: Teaching Makes Me Stronger

Outside the outskirts of Seireitei, two Shinigami wearing white haori had just finished collecting Reiatsu.

They each held several blue glass tubes filled with the gathered Reiatsu.

"I'm done on my side."

"Same here. We got lucky this time. We even managed to supplement the data on Unohana Retsu."

"Yeah. Unohana Retsu rarely takes action these days. Getting a reading of her Reiatsu in combat is no easy feat."

"Looks like we'll be adding two more companions to the fold. Those initial generation prototypes had no self-awareness at all, actually trying to provoke her original body."

"Heh, those first-generation shells should've been scrapped. Otherwise, one day they'll end up dragging us down."

"Don't say that… Without the first-gen Reishi Shells, we wouldn't even exist."

"That's different."

"Still, it's a shame our power can't grow properly."

After exchanging a few words, the two departed the forest.

What they didn't know was that something had already joined their shadows.

Nanatsuki had arrived in the forest and slipped into the shadow of the Kyōraku Shunsui shell.

He'd overheard the two speaking and fell into deep thought.

It seemed this "Kyōraku Shunsui" and "Ukitake Jūshirō" weren't made with the first-generation Reishi Shell technology.

'Has the shell tech been upgraded?' Nanatsuki frowned inwardly.

From what he knew, there were very few individuals or factions capable of advancing Reishi Shell technology.

Curious about who was behind the research, he chose not to destroy the two shells immediately.

They were heading toward a familiar place—Squad 12!

"Kyōraku Shunsui" and "Ukitake Jūshirō" arrived near Squad 12, where a bizarre-looking Shinigami had been waiting for some time.

His appearance was barely human. His head was large, his eyes looked ready to pop from their sockets, and his skin was green. He wore a lab coat typically seen on researchers.

Nanatsuki vaguely recognized the frog-like Shinigami. He had seen him before in Hikifune Kirio's lab.

But he couldn't recall his name.

'So they're even connected to Squad 12's researchers now...' Nanatsuki's brow furrowed. In his past life's memories, this frog Shinigami had nothing to do with the Reishi Shells.

The frog Shinigami's presence made Nanatsuki realize—his transmigration might've already caused deep changes to this world.

"You got the samples?" the frog Shinigami asked.

"Collected." One of them handed over the blue glass tubes.

The frog Shinigami accepted them and directly stuffed the tubes into the shell's body.

"Excellent. With these Reishi, we'll be welcoming new companions again." With that, the frog Shinigami parted ways with the two and said, "I'll head back first."

As he and "Kyōraku Shunsui" brushed past each other, the shadow beneath them silently shifted direction—Nanatsuki had now entered the frog Shinigami's shadow.

The frog Shinigami returned to Squad 12, walking openly through the main gate.

Along the way, he even greeted passing Shinigami soldiers.

Near Hikifune Kirio's lab, he ran into Urahara Kisuke.

Urahara Kisuke greeted him warmly. "Yo, Kazushu, did the data comparison check out?"

The frog Shinigami peeled back his lips to reveal two neat rows of teeth. "It's done. Asayu Tetsuya wasn't lying. He really did visit all those locations the day before. But… he also went to the Shin'o Spiritual Arts Academy, and Squad 8 has already found a witness."

To verify Asayu Tetsuya's statements, Urahara Kisuke had built a lie detector of his own—one that could monitor a soul's vital indicators to detect falsehoods.

Urahara scratched his face. "Looks like this lie detector isn't all that reliable. Some folks can lie without batting an eye."

"It's still quite useful. Most people don't have that kind of mental composure." The frog Shinigami nodded and stepped into the elevator with Urahara.

"Then I'll take that as a compliment," Urahara chuckled. He suddenly asked offhandedly, "By the way, Kazushu, I thought I saw you walking into a side alley with Captain Kyōraku and Captain Ukitake just now…?"

The frog Shinigami's hand paused for a moment over the elevator buttons. But he quickly regained composure, pressed the button for B3, and explained, "Oh, Captain Kyōraku is still investigating Asayu Tetsuya. He came to ask if I had found anything in the lab."

"I see... Captain Kyōraku being so proactive is a rare sight." Urahara smiled and said nothing more.

Despite his carefree tone, Urahara Kisuke had already grown suspicious of the frog Shinigami from their repeated lab interactions. Still, he hadn't yet begun a formal investigation or found any real dirt on him.

Nanatsuki, having overheard their conversation, thought Urahara may have sensed something was off.

The three of them took the elevator down to Hikifune Kirio's lab.

Just as Urahara and the frog Shinigami stepped through the lab's door, the overhead lights began to flicker.

"Alert—Alert—Unauthorized intruder detected—"

There was an invisible wall of Reishi at the entrance to Hikifune Kirio's lab. Only those with authorized access could pass through without triggering the alarm.

The last time Nanatsuki visited, Hikifune had disabled the barrier, so he hadn't known it existed.

The siren quickly alerted all the lab researchers—Hikifune Kirio included.

"An intruder?! Where?!"

Hikifune rushed to the door but only saw Urahara Kisuke and the frog Shinigami.

"Wasn't me~" Urahara raised both hands as if surrendering, casting a mischievous glance at the frog Shinigami. "Kazushu... you didn't bring something unclean in, did you?"

The invisible Reishi wall now glowed red, clearly marking the frog Shinigami as the source.

At that moment, a shadow slowly rose from the ground and took the form of Nanatsuki.

"That's kind of rude, Urahara-kun. I'm not some unclean thing, you know!" Nanatsuki grinned.

He could've hidden deeper in the shadows to avoid detection—but he chose to reveal himself.

The frog Shinigami was a researcher in Hikifune Kirio's lab, and thus had access to critical tech. Letting him stay here any longer would be far too dangerous.

So Nanatsuki chose to expose him.

The frog Shinigami's expression darkened—he'd actually been tailed by Katori Nanatsuki!

And he had no idea when the tailing had even begun!