Kikyo's situation wasn't caused by any strange jutsu. She had simply been granted certain permissions within the spiritual network world by Uchiha Kei.
This permission was called "building mode," allowing Kikyo to construct any structures she liked, much like a sandbox game with high freedom and block-placing mechanics.
Such games were often nicknamed "block-building" or "farming" games. As the first person Kei gave permissions to in the mental network, once Kikyo learned the basics of how this world worked, she began experimenting with building homes—and quickly became addicted to it.
This grassland was an intentionally open area created by Kei. Everyone who entered the spiritual network landed here.
Of course, this grassland wasn't the only zone in the network. Kei could expand it if he wanted, but it wasn't necessary. His game, My World 3.0, was developed in a separate dimension, so nothing here would interfere with his genjutsu game development.
After Kei explained all this, Minato Namikaze finally understood how amazing this domain was. A look of surprise spread across his face. "You can even build houses here? What else can you do?"
Kei asked back, "Did the genjutsu game feel real to you?"
Minato nodded. "Of course it did."
"Then that's your answer," Kei said. "You can treat this place as a real second world."
Minato's eyes widened. His brain stalled.
After all, for someone whose worldview was still limited to the Five Great Nations and a few smaller ones, the concept of a 'second world' was too revolutionary. He couldn't imagine what could be done here.
Or rather—just imagining a few possibilities made his scalp tingle and his heart skip a beat.
Kei smiled. "Minato, let me tell you how essential this world is to you. First off, you can enjoy a peaceful, undisturbed world with Kushina—no explanation needed."
"If you want to develop a new jutsu, no matter how dangerous, you can test it here freely before trying it in the real world."
"See that giant library? It contains knowledge beyond what exists in the shinobi world. Orochimaru-senpai fell in love with it and now studies in there every day."
"In fact, he's inside right now."
"You can go study too. The 'radical' ideas I once mentioned to you? You'll find complete theories and case studies in that library."
"This place will become our special domain—whether it's to change the world, create something new, or seek the truth of knowledge to grow stronger, it can all be done in this second world."
Kei's words stirred Minato's heart. His breathing quickened.
Guided by Kei's words, Minato began to imagine other uses for this domain. Countless things that once seemed delusional now felt possible.
He took a deep breath and asked seriously, "Kei, who else knows about this?"
Kei replied, "Only those who can enter it—right now, that's you, Kikyo, and Orochimaru-senpai."
Minato nodded firmly. "Understood. This is our secret."
A clear promise—Minato wouldn't tell anyone else.
Kei smiled. "Actually, it's fine to tell Kushina. I've already reserved a slot for her. But you know her condition—unless I'm confident, I can't let her in."
Minato's face darkened slightly. "Yeah. The Nine-Tails is a real problem. She can't even play the genjutsu game..."
He sighed.
As the Nine-Tails' jinchūriki, Kushina had to constantly suppress the beast sealed within her. It made entering a genjutsu-based world too dangerous—no one could guarantee the Nine-Tails wouldn't break free.
Even though Kushina was a direct descendant of the Uzumaki Clan, inheritor of their sealing techniques, and even chosen by Princess Mito Uzumaki herself, her seal wasn't as stable as her son Naruto's would be in the future.
That made the Nine-Tails a constant threat. If Minato wasn't by her side, the village assigned elite Anbu to monitor and guard her, effectively placing her under semi-house arrest.
It wasn't humane, but it was necessary. In the Naruto side story Minato's Tale, Kushina once snuck out while the Anbu weren't paying attention, and the Nine-Tails nearly went berserk, almost costing Minato his life.
If Minato hadn't risked entering her mind to help suppress the beast, the village might've lost both its future Fourth Hokage and the Nine-Tails' jinchūriki that day.
That story alone shows how miraculous Naruto's later peaceful life really was. Given the Nine-Tails' danger, the logical response would've been to keep Naruto under lock and key.
Yet Hiruzen Sarutobi let him roam free in the village—and even banned anyone from targeting him. Honestly, everyone who knew the truth thought Hiruzen had lost his mind.
It's worth noting that Naruto's childhood differed wildly between the manga and anime.
In the manga, Naruto lived like a wild second-generation rich kid. His house had everything he needed—it was the same home his parents had lived in. The rumor that Hiruzen stole Naruto's inheritance? Pure fiction.
People feared and resented Naruto, but they didn't dare confront him directly. Even when villagers cursed him, it was always behind his back—not to his face. No one wanted to get on the bad side of the Nine-Tails jinchūriki.
He never went hungry or had to buy expired food. The milk spoiled because he left it out too long.
The extent of the villagers' malice was more like "guess who wasn't invited" levels of cold shoulder. Anyone who tried something more direct likely got a visit from the Anbu.
Hiruzen actually did seal Naruto's identity as a jinchūriki. Even Orochimaru didn't find out until the Chūnin Exams when Naruto lost control of the Nine-Tails' chakra.
All in all, the manga's Hiruzen really did try to give Naruto the best life possible.
Compare that to Killer Bee—also a jinchūriki, also the son of a Kage-level figure—and his childhood was brutal.
Now, the anime… went a little overboard. To make Naruto seem more pitiful, they portrayed him as constantly bullied, shunned, and insulted to his face. He couldn't even buy food. Totally at odds with the manga.
If the two versions of Naruto met, they'd probably roast each other.
"Why was your childhood so good?"
"Why was yours so miserable?"
But back on topic: Minato was a sealing technique genius—the best in the village. Better than even Kikyo or Kushina.
Kei asked, "Minato, have you thought about strengthening Kushina's seal? Like combining two Four Symbols Seals into a more powerful one?"
Minato froze, then began thinking deeply.
Every time Kei spoke like that, it meant something was highly feasible. Minato's job now was to make that theory reality.
Meanwhile, Kei tapped a few commands on a system panel only he could see. Moments later, a group of identical NPCs materialized nearby, startling both Minato and Kikyo.
Minato: "Kei, what is this...?"
Kei: "These are simulated people—physically and biologically identical to real humans. You can test your sealing techniques on them without worrying about harming anyone."
Minato's eyes lit up. "Thanks, Kei."
Kei waved it off. "C'mon, we're bros—no need for thanks. The stuff's all here, and I've marked out a space for you. I'm giving you a spiritual seed. You can access this domain anytime through it—no need to find me."
"Now let's hit the library. I've bookmarked the books you'll need. From now on, you can grab them directly whenever you come to study."
Minato nodded eagerly and followed Kei to the library.
Kikyo, meanwhile, after curiously examining the newly spawned NPCs, waved to them and returned to building her dream house.
She was completely hooked on "block-building." It had a stronger draw than any genjutsu game so far.
After all, in her heart, she wanted to personally build a home for herself and Kei.
Elsewhere in the library, Minato spotted Orochimaru deeply engrossed in a book. He flipped pages at varying speeds and occasionally nodded with sudden clarity, as if reaching enlightenment.
Piles of books surrounded him, carefully selected for study.
Kei whispered to Minato, "Better not disturb Orochimaru-senpai. He gets mad when interrupted while reading."
Minato nodded without protest. The two headed for another section—focused on culture, politics, and war.
Kei quickly pulled out a selection of representative books, some of which even covered history. When it came to Minato, there was no need to censor sensitive content. A true best friend wouldn't need things explained—they'd understand and fill in the blanks themselves.
The bonds of the Leaf... pretty amazing, huh?