Scene: Mizuki's Home, Evening
The sun had long since dipped beneath the horizon by the time Mizuki returned from his mission. His fiancée, Tsubaki, had already prepared dinner and was waiting patiently.
"How did it go today? I heard Anko Mitarashi was leading the team," she asked, setting plates on the table.
"It went well. Nothing special, really," Mizuki replied, removing his flak jacket and stretching his arms. "The mission was supposed to take ten days, but we've got a few more chūnin helping now. If we push harder, we might wrap up early."
"That's good to hear. I also heard Iruka was assigned to the same mission. Did you two get along today?"
"Don't worry about it. It was fine," Mizuki answered, voice neutral.
Tsubaki smiled with quiet relief. "By the way, I sorted out some old documents on sealing techniques. I left them on your desk. Maybe they'll be useful."
"Thanks, Tsubaki." Mizuki's expression softened. "Let's eat first."
"Mm, alright."
Just then, a knock came at the door.
"At this hour? Who could it be?"
Mizuki opened the door to find Iruka Umino standing there, scroll in hand.
"Yo, Iruka. What brings you here?"
"Evening. I won't stay long. Just came to drop this off," Iruka said, holding out the scroll.
Tsubaki called from inside, "Iruka? Want to join us for dinner?"
"No thanks, I need to get back. This scroll—it contains a few basic sealing jutsu. Simple ones, but might be helpful."
Mizuki raised an eyebrow. "How did you know I was looking into sealing?"
"We've been friends for over ten years, Mizuki. I can tell when you're up to something. You've been muttering about seal arrays lately. Hard not to notice."
Mizuki sighed. "You're still too good for your own good."
Without a word, Mizuki stepped inside and returned with two scrolls. He tossed them toward Iruka.
"Here. Notes on genjutsu application and a little on puppetry and toxicology. Nothing groundbreaking, but you'll find use for it."
Iruka blinked. "Mizuki, I didn't give you that scroll expecting anything in return—"
"I know. That's exactly why I can't let it slide. Consider us even."
Iruka chuckled. "Then I won't refuse. Thanks."
"Don't mention it. Focus on finishing the mission."
"I will. See you around."
"Iruka, wait—" Mizuki hesitated, then added, "I owe you one for this. If you ever need anything, come to me."
Iruka smiled, not quite realizing the weight behind Mizuki's words. "Sure. See you tomorrow."
Later That Night
After Iruka left, Mizuki leaned against the window, watching the quiet village. Tsubaki hummed softly as she cleared the table.
"The peace here... it won't last," Mizuki murmured. His eyes drifted to the flowerpots by the window. Among them were several ordinary-looking plants—kudzu, bamboo, and a thorny vine he'd found in the Forest of Death. But exposure to chakra over the past few days had altered them. The kudzu now regenerated with frightening speed. The thorny vine—resembling a nepenthes—had started to lure and consume sparrows. Even the bamboo had hardened into a tougher, weaponizable form.
Yet none of that compared to what floated in the glass tank in the middle of the room: translucent, ethereal jellyfish—each with a glowing red core.
He had bought them from a foreign merchant at the night market. According to the vendor, they were highly poisonous. But Mizuki saw something else—an echo of a memory from a different lifetime. These jellyfish shared properties with the Turritopsis dohrnii—the so-called "immortal jellyfish" from his past life.
Under chakra-rich conditions, they not only adapted but reverted to polyp form repeatedly. Even after splitting, the clone retained Mizuki's summoning contract seal. That confirmed it: regenerative cloning that didn't reset contracts. Reverse growth was real.
"If Orochimaru knew about this..." Mizuki whispered. "He'd find a way to weaponize it into a true Rebirth Technique."
But unlike Orochimaru's obsession, Mizuki was more measured. He wasn't seeking immortality out of ambition—he sought control, security.
Using chakra to simulate a stable growth environment, Mizuki had set up seal arrays around the windowsill and tank. They weren't battle-grade, but they concentrated chakra to stimulate growth. His experiments had reached the stage of basic seals—fire seals, storage seals, weak binding arrays. More complex ones—like the Four Symbols Seal or the Five Elements Seal—remained beyond his reach. Spiritual-based seals, tied to Yin chakra, were barely scratched.
Still, it was progress. The Ninja World treated biotechnology as crude—organ transplants, forced mutations, Kekkei Genkai implants. No one had pursued precise manipulation. Chakra made crude success easier than careful refinement. Why decode a gene when you could crush results together until something worked?
He activated the formation array once more, watching the glow intensify, reinforcing the chakra-rich zone. Satisfied that the jellyfish were healthy, he stepped out into the street. There was nothing more to do tonight. Perhaps another stroll would yield another strange, forgotten treasure—like the jellyfish.
Meanwhile, in the Hokage's Office
The Third Hokage, Hiruzen Sarutobi, tapped his pipe against the windowsill as he read the Anbu report.
"Nothing suspicious from Mizuki?" he asked.
"No, Lord Third. We monitored his Forest of Death mission closely. Anko Mitarashi led the team. Nothing irregular reported."
"What about his activities since returning?"
"Mostly at home. Some time on the street. Only regular contact has been with Iruka Umino and his fiancée, Tsubaki."
"No clandestine meetings?"
"None. He's been purchasing common plants and poisons from street vendors—everything accounted for. He's keeping them at home now. Our report lists them in detail."
The Third's eyes narrowed. "Jellyfish? Why?"
"Kept in a fish tank. No hostile usage. Possibly studying poison extraction."
Hiruzen reviewed Mizuki's file. A civilian-born ninja, no clan heritage, elemental affinity: Fire. Lacked advanced ninjutsu. Known for minor success using poisons in past missions.
"Hmph. Likely developing a niche. Nothing alarming yet."
After a pause, he gave his orders. "Cancel full-time surveillance. Shift to area-specific monitoring. When his vacation ends, assign him to the mission task desk. All B-rank or higher missions Mizuki handles must come through me."
"Yes, Lord Hokage."