Konoha: Uchiha's Two-Way Travel in One Piece

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On Kaito's side

As time passed, his body grew stronger by the day.

With the nourishment of specialized medicines and Sea King meat, combined with the effects of his Longevity cultivation technique, his life essence was recovering rapidly. Even his height increased noticeably.

Four days later, Kureha successfully developed super-nutrition potions and body-strengthening tonics.

In just two days, Kaito used these formulas to create diluted versions with varying effectiveness, such as 10%, 20%, 50%, and 80% potency.

Additionally, he combined Sea King meat with certain medicinal ingredients to craft nutrient pills. He then created a series of weakening formulas for these pills, ranging from 10% to 90% strength.

After another seven days, he successfully diluted and refined recovery tonics aimed at healing hidden injuries and restoring vitality.

Building on these, he merged the effects of nutrient pills and potions to create a gentle, highly effective formula capable of quickly replenishing life force. He named this the Life Elixir.

"This elixir should perfectly solve Uzumaki Mito's problem!" he thought, gazing at the gentle, vitality-filled potion in his hand.

"Assuming her issue is purely excessive life force depletion."

By now, Uchiha Kaito's medical skills had reached the intermediate level and were steadily improving. His progress in other areas was equally significant.

"Oh? This potion isn't bad at all! It's especially useful for ninjas like you who extract this special energy," Kureha remarked, walking over with a curious smile.

"With this, you might just avoid burning through your lifespan during combat! But… this isn't cheap, is it?"

Kaito nodded affirmatively. "Not at all. It requires a massive amount of Sea King meat and rare medicinal ingredients. The extraction and refinement process is also incredibly intricate and time-consuming. Converted to Belly, the cost is around 5 million per vial!"

"If we can optimize the extraction process and streamline production, the cost could drop significantly—but that won't happen overnight."

For now, mechanical manufacturing and engineering were beyond his expertise. Developing advanced production lines was out of the question.

"Maybe I could collaborate with Orochimaru?" he mused.

But the idea was quickly dismissed.

"No, he's not quite there yet in terms of research capabilities. Besides, he's still loyal to the Third Hokage—it's not the right time."

"Perhaps I should seek solutions in the One Piece world. For example, obtaining technology from Germa 66?"

Of course, with his current strength, that was impossible. For now, he'd have to rely on his mother.

"Mom already has enough on her plate. This Life Elixir isn't urgent—better to shelve it for now."

He sighed inwardly.

"If only I had powerful and trustworthy allies!"

Fortunately, he didn't need the elixir himself at the moment. His recovery was progressing well enough with nutrient potions and pills.

"It's already impressive," Kureha commented, shaking her head slightly. "The stronger the potion, the harder it is to refine—that's something you should know by now."

"In a few days, you'll be fully recovered. Don't forget, you still owe me quite a few medical texts. You'll be visiting often, right?"

So far, the books Kaito had given her totaled fewer than 200 volumes. While incredibly beneficial, they were far from satisfying her curiosity.

"Of course," Kaito said with a smile. "You can count on me. Even after recovering, I'm not strong enough to roam freely out at sea. Besides, I still have thousands of your medical texts to study, and I've yet to master your techniques. There's no way I'm giving up on that!"

His plan was to fully tap into Kureha's expertise—and raise her goodwill towards him to 80 points or higher.

Currently, her goodwill was at 72 points—a promising start.

"Give me a few more months, and I should reach my goal," he thought.

Although raising goodwill became harder as it increased, frequent exchanges of knowledge and interactions would gradually do the trick.

Kureha laughed heartily. "You're a greedy one! It won't be easy to learn everything I know. Be prepared to stay here long-term!"

With that, she returned to her recliner and resumed reading.

Another few days passed, and Kaito had been on Drum Island for almost a month.

Finally, his body was fully healed.

The congenital deficiencies in his life essence had been completely resolved. In fact, thanks to his Longevity cultivation technique and the restorative process, his life essence now surpassed that of an average person.

His physical strength was several times greater than that of his peers in the ninja world.

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[Uchiha Kaito]

Talent: Dimensional Gate, Effort Brings Reward

Lifespan: 95 years, 7 months, and 19 days (Life Essence: 13.2)

Chakra Attributes: Water, Wind, Fire, Earth, Yin, Yang

Skills: Uchiha Chakra Refinement (1/100, Beginner), Medical Skills (7,568/50,000, Intermediate), Longevity Cultivation Technique (5,145/10,000, Advanced), Uchiha Meditation (456/1,000, Proficient), Basic Taijutsu (342/500, Skilled)

"Haha! I'm finally healthy again! My lifespan has reached over 95 years, and with more cultivation, I might break 100 soon!"

Seeing his updated attributes, Kaito felt a wave of relief. The past month had been a grueling but rewarding journey.

"Now, I can officially start training in chakra, ninjutsu, taijutsu, as well as the Six Powers and Haki."

Of course, everything needed to be approached gradually. For example, training in the Six Powers and Haki would require carefully tailored plans to avoid overstraining his body.

Even with nutrient pills and potions, chakra training needed to remain within reasonable limits.

"Huh? I awakened the Yang attribute too? What a pleasant surprise!"

"This will make learning medical ninjutsu and Yang Release techniques much easier!"

"This must be due to the Sea King meat restoring my vitality and enhancing my life essence," he speculated.

It was an unexpected but welcome development.

"Only lightning remains for full elemental mastery. Maybe eating the Rumble-Rumble Fruit will unlock it?"

Kaito couldn't help but imagine.

However, he hesitated. Eating a Devil Fruit would come with a significant weakness. While ninja-world water wouldn't affect him, the seawater of the One Piece world was a real concern—especially since he planned to conquer that world someday.

"Is there a way to eliminate this weakness? Sigh, I'll deal with that later."

Setting aside the thought, Kaito called for Mikoto. After bidding Kureha farewell, the two returned to their home in the ninja world.

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