Naruto Uzumaki was still trying to make sense of what was going on in the classroom. When he saw Iruka-sensei storm out in a hurry, he thought it was time to goof off.
"What's everyone doing?!" Naruto shouted. "Iruka-sensei's gone, so let's get wild and paint the town red!!!"
With that, Naruto leapt onto a desk, full of energy.
Sasuke Uchiha, watching the scene unfold, stayed on guard, his hand tightly gripping a kunai.
"That idiot!!!" Sasuke muttered under his breath.
Sakura Haruno, on the other hand, was fuming. She stormed toward Naruto, who was thrilled to see his crush heading his way, his heart practically doing backflips.
"Sakura!!!" Naruto beamed.
WHAM!!!
Sakura jumped up and landed a solid punch on Naruto's head.
"Naruto Uzumaki!!! Be quiet for once! Hirofumi Ito is gone!!!" she yelled.
"Ow, Sakura, what was that for?!" Naruto whined, rubbing his head. "Wait, what?! Who's gone?!"
Naruto immediately quieted down, his eyes darting to Hirofumi Ito's seat.
"Hirofumi's gone!!!" Sakura snapped. "So just shut up for a second! Iruka-sensei's already gone to get the Hokage!"
"What?! How could he just disappear?!" Naruto said, staring at the empty seat in disbelief.
Hirofumi Ito was one of Naruto's few real friends. The guy never cared that Naruto was the Nine-Tails' jinchuriki and even shared his snacks with him. How could someone like that just vanish?!
Soon enough, the Third Hokage, Hiruzen Sarutobi, arrived with Iruka, his expression grim.
Iruka had already filled him in, and Hiruzen had a hunch about what happened to Hirofumi.
"Did anyone see exactly what happened?!" Hiruzen asked the class.
Ino Yamanaka hesitantly raised her hand.
"Lord Hokage… I saw it," she said softly. "Iruka-sensei was teaching us about summoning jutsu and the hand signs. Then I saw Hirofumi start forming the signs, and—poof!—he just disappeared!"
Hiruzen and Iruka exchanged a glance, both saying the same thing at the same time: "Reverse Summoning!!!"
"Iruka," Hiruzen said.
"Yes, Lord Hokage?"
"Go inform Aoyama Ito, Hirofumi's father and the head of the Ito clan, about this. Reverse summoning… there's no easy fix for this. We don't know where the boy was summoned to or if he can even come back…"
"Understood, Lord Hokage!" Iruka replied, hurrying out.
Hiruzen lit his pipe, puffing out clouds of smoke as he stared at Hirofumi's empty seat. His thoughts drifted to his old student, Jiraiya.
Back in the day, Jiraiya had been reverse-summoned to Mount Myoboku, where he learned sage arts and soared to greatness. Could Hirofumi Ito have stumbled into a similar opportunity?
Meanwhile, Hirofumi Ito was freaking out.
He'd just been practicing a summoning jutsu, and now he was in some unknown place! It was foggy, dark, and cold, with no sun or light—just endless darkness and an eerie chill.
"What the heck is going on?!" Hirofumi yelled. "Did I get reverse-summoned?! Is this some kind of sacred place?! But there's no toads, no slugs, no snakes—nothing! How am I supposed to get back?!"
[Host detected. System binding successful!
Host location: Hidden Leaf Village.
Binding Host to the Spirits of the Leaf…
Binding successful!]
"Wait, what?! A system?!" Hirofumi exclaimed.
"System, what's going on?! Why did you bind to me all of a sudden? Where am I? And what's this about binding to the spirits of the Leaf?!"
[Host was originally destined to die!
In the original timeline, the Host was meant to perish in the womb, with their soul entering the Spirit Realm of this world.
Due to an unknown error during Host detection, this System infiltrated the Spirit Realm, breaking through the barriers between worlds to successfully bind with the Host!]
Hirofumi was stunned. No wonder he didn't exist in the original story—he was supposed to have died before he was even born! His穿越 (transmigration) must've changed things, allowing him to be born as Hirofumi Ito.
"So, you're saying I was supposed to be a spirit, and you went to the Spirit Realm to find me, but since I'm alive, you broke through the barriers to reach me?" he asked, piecing it together.
"System, what kind of system are you?!"
[This System was originally a "Many Children, Many Blessings" System!
However, due to consuming too much energy while absorbing the Spirit Realm, the System can no longer grant the Host the "Many Children, Many Blessings" function.
During the fusion with the Spirit Realm, an unknown change occurred!
The System can now bind spirits to the Host, making them the Host's summoned beasts!]
Hirofumi had to admit, the "Many Children, Many Blessings" thing sounded pretty cool, but with the system glitching out, that was off the table. Still, binding spirits? What was that about?
"System, are you saying I'm in the Spirit Realm right now?!"
[Correct! When the Host was practicing the summoning jutsu, this System reverse-summoned the Host to the Spirit Realm and successfully bound the entire Spirit Realm to the Host!]
"Wait a sec, didn't you say I was bound to the spirits of the Hidden Leaf? Now you're saying it's the whole Spirit Realm?!"
[Since the Host is currently a resident of the Hidden Leaf Village, the Host can summon the spirits of the Hidden Leaf.
If the Host gains full control over the ninja world, the entire Spirit Realm can be fully bound to the Host!]
"Oh, I get it now," Hirofumi said, nodding. "Alright, System, tell me about your functions!"
[This System was originally a "Many Children, Many Blessings" System, but due to an unknown error, it has transformed!
It is now a Summoning System!
The Host can use summoning jutsu to summon spirits as their summoned beasts!
White-tier summons: Genin-level ninja spirits.
Green-tier summons: Chunin-level ninja spirits.
Blue-tier summons: Jonin-level ninja spirits.
Purple-tier summons: Elite Jonin-level ninja spirits.
Gold-tier summons: Hokage-level ninja spirits!]