The annual opening day of the Ninja Academy had finally arrived.
Hoshiyomi had been waiting for this day for a long time—for one simple reason:
This year, Naruto and the others had turned six and would finally be entering the Academy.
With the Konoha Twelve starting school, his "Genius Training Camp" could officially close for good.
These past months had truly exhausted him.
Originally, he'd only taught Naruto and the others occasionally out of interest.
Who would have thought things would escalate to the point where the entire Gekko household became a giant daycare center?
Teaching one kid or two wasn't an issue—but handling nearly twenty children of different ages at once?
Who on earth could survive that?
To ensure he really wouldn't have to continue acting as daycare manager, Hoshiyomi woke up early and brought his twins to observe the Academy's entrance ceremony.
Up in a tree, Hoshiyomi was holding Rinne while watching the bustling crowd of parents and children below. Ryūshin sat on a branch with a miniature version of Mikazuki Munechika resting on his lap, spacing out—clearly uninterested in "school ceremonies."
Rinne, snuggled in Hoshiyomi's arms, was the excited one. She looked down at the crowd, earnestly searching for familiar faces.
"Daddy, look! I see big bro Naruto and Aunt Kushina!"
Rinne suddenly stood up in Hoshiyomi's lap, pointing excitedly at Naruto and Kushina below.
"Daddy?"
She called twice, noticing her father wasn't responding.
Confused, she turned around—only to see his very strange expression as he tried to sit her back down onto his thigh.
Hoshiyomi had been in a good mood watching the kids below and hadn't noticed his daughter's movement.
But Rinne, thrilled at seeing Naruto, had suddenly stood up.
With her inherited monstrous strength, that one excited stomp of her foot landed squarely on Hoshiyomi's body.
Caught completely off guard, Hoshiyomi nearly fell out of the tree.
Fortunately, he only had his daughter on one thigh and not directly in the center; otherwise, one stomp from his daughter would have meant he wouldn't be a father for the rest of his life, and Rinne would have joyfully acquired a second mother.
Though he was internally injured, Hoshiyomi forced a smile when he saw his daughter's puzzled gaze:
""It's nothing, Daddy just spaced out. But jumping around on a tree is dangerous, little Rinne. Sit properly."
Rinne tilted her head in confusion but obediently sat back down.
Ryūshin, meanwhile, wasn't sympathetic at all.
He simply watched with a half-smirk, which only annoyed Hoshiyomi further.
The entrance ceremony ended with Minato's speech, and Naruto and the rest of the "Little Twelve" followed Iruka into their classroom.
Hoshiyomi then took his twins home.
With the Ninja Academy starting, not only the other children but even Haku and Kimimaro had gone to class, and the Gekkō household was a rare picture of quiet.
With the Genius Training Camp officially over, Hoshiyomi finally had time of his own again.
After giving Ryūshin some sword lessons and telling him to practice on his own, he left Rinne in Tsunade's care and headed to Orochimaru's laboratory.
Now that he finally had free time, two long-delayed matters resurfaced in his mind—
One of them being whether it was possible to use Yin Release chakra to evolve a Mangekyō Sharingan into an Eternal Mangekyō.
Back then, the experiment had to be abandoned because Shin was still too young.
Now four years had passed, and Shin was already twelve—old enough for a Sharingan transplant.
So Hoshiyomi planned to use his free time to finally test the hypothesis he had made four years ago.
The other matter was—
"I had been planning to invite Hoshiyomi-kun over myself, but I didn't expect you to come on your own."
After hearing Hoshiyomi's reason for visiting, Orochimaru showed a smile, then stood up.
"Come with me. Garuru is currently undergoing basic testing in Laboratory No. 2."
Hearing this, Hoshiyomi rubbed his hands together excitedly and quickly followed Orochimaru to the so-called Lab 2.
When Orochimaru entered the password, the high-tech metallic door slowly opened, revealing a massive metal wolf lying quietly on the floor.
It was Garuru—the youngest child of Lobo—Hoshiyomi's summoned beast.
Though now, he should be called MetalGarurumon.
Garuru's entire body was covered in metal armor.
Even his tail was layered with tightly fitted plating, and on his back rested a pair of exaggerated mechanical wings.
Just one glance was enough to send chills down one's spine.
The concept of "MetalGarurumon" was born the moment Hoshiyomi gave him that name.
After years of waiting, that concept had finally become reality.
The moment Hoshiyomi entered, Garuru sensed the familiar scent on him.
He sniffed the air lightly, and excitement flickered in his glowing green eyes.
With a clatter of metal, Garuru rushed to Hoshiyomi's side, rubbing enthusiastically against his leg.
Hoshiyomi's eyes shone even brighter than Garuru's as he looked at the metallic sheen covering the wolf.
Caressing the cold metal armor on Garuru's back, only one word remained in Hoshiyomi's mind: Cool.
Orochimaru, standing beside Hoshiyomi, looked quite pleased with Hoshiyomi's fond reaction. As Hoshiyomi stroked Garuru's armor, Orochimaru softly explained the functions of the various parts of the armor:
"The MetalGarurumon concept is truly ahead of its time. I never imagined it was possible to install armor on a summoned beast.
When I first saw the schematics you sent, I thought it was pure fantasy.
But the deeper I researched, the more I realized many parts of the design were actually feasible after minor adjustments."
Pointing at the device on Garuru's back, Orochimaru said:
"For example, these metal wings.
They're made from chakra metal fused with several special alloys, creating a new compound.
Its hardness surpasses refined steel—and more importantly, it has excellent chakra conductivity.
In my tests, as long as Garuru continuously outputs Wind Release chakra, these wings really can enable short-distance low-altitude gliding.
And those cannons on his shoulders—when infused with enough chakra, the left one can fire compressed wind shots similar to Vacuum Bullets.
The right one can emit flames.
Since Garuru doesn't have Fire Release chakra, the flame output uses a Fire-style jutsu scroll built into the mechanism.
The switch is located beneath Garuru's left paw, allowing him to fire at will."
Author's Note: (I remember the movies, fillers, and games all had concepts like Mecha Naruto and Mecha Nine-Tails, so a mechanical Garuru is definitely plausible.)