Shoot's rapid growth was simple: his battles against monsters and mercenaries in the other world had dramatically increased his strength. This significant increase in power and skill level directly impacted his physical growth. Because of the rapid and substantial power increase, his body experienced rapid growth in response.

Shoot’s appearance had transformed into that of a high school or university student (17-19 years old), making him look far older than a middle schooler.

“My face… still somewhat resembles my old self. I’ve grown taller, so no one will recognize me immediately.”

He whispered, “Even my parents…” Even his parents, who’d shown little interest in him lately, wouldn’t recognize him immediately, he chuckled self-deprecatingly.

He ate breakfast alone again this morning. It was Sunday, a school holiday. Most people had the day off, but Shoot’s parents were staying at the company again, leaving him alone at home.

Still adjusting to his sudden growth spurt, he was grateful for their absence but also somewhat curious about their reaction when they returned.

“It’s Sunday, and school starts tomorrow… I’m strong enough to crush those scumbags now, but I want to grow even stronger. I want more abilities. Then I can torment them even more…!”

Imagining himself inflicting torment on Nakazato and his gang, Shoot grinned, his eyes sharp as a hawk’s. He felt that his current strength wasn't enough to achieve his fantasies and decided to go to the other world again.

“…Let me organize what I know about the other world.”

He took out a blank notebook and wrote down everything he knew.

—About the Other World—

• The way to travel to the other world is to enter the mysterious black vortex in my basement. The vortex itself is chaotic, but harmless.
• The location of the vortex’s destination is random each time, and the destination is unpredictable.
• The civilizations of the other world and this world are completely different. There’s probably no country like Japan in the other world.
• Monsters (goblins, slimes, dark red wolves, etc.) that don't exist in this world are present. They are all dangerous. I might get killed if I’m careless.
• When I perform various actions in the other world, I inexplicably acquire “skills.” (Running continuously makes me incredibly fast; punching a lot gives me martial arts; swinging weapons grants me swordsmanship, etc.)
• There are many conditions for skill acquisition, so I should try various actions in the other world.
• No matter how long I spend in the other world, time barely passes in this world.
• Conversely, no matter how much time passes in this world, time in the other world might not change… (I should investigate this further).
• The way back to this world is to enter the black vortex. So far, it always returns me to my basement.
• Items obtained in the other world cannot be brought back. Everything disappears upon returning. So I need to store obtained items and equipment somewhere in the other world.
• There are mercenaries in the other world who can apparently make a decent living.
• The ore obtained from monsters is called “Strange Ore” and can be exchanged for money in the other world.
• There is no electricity or gas in the other world. But I might be able to use magic to get those.
• The strength I gain in the other world carries over to this world. So, I remain strong here.
• Similarly, the increased strength in the other world caused physical growth. But this might be a one-time thing.
• I have no idea why I can travel to the other world from my basement. I don’t know if there are other black vortexes leading to other worlds.

“…I think that covers it.”

Having finished writing, Shoot reviewed his notes, committing everything to memory.

“I shouldn’t return with rare items in my backpack. Also, I didn’t wear them yesterday, so I was fine, but if I return wearing clothes I made in the other world, they might disappear, so I have to be careful.”

Having reminded himself of these precautions, he went to the basement.

“I should avoid going to the other world for a while, except maybe one last time before school tomorrow. From tomorrow, I want to use my otherworldly powers in this world.”

Shoot slapped his cheeks, setting his mindset.

“I… no, I will use this power to take revenge on those who made me suffer.

And from now on, I’ll do as I please with this power!”

Shoot had transformed from a weak and powerless “boku” (I, used by boys and men) to a strong and arrogant “ore” (I, more assertive, often used by men) – forging a strong and confident self. His physical transformation had prompted an equally drastic change in his personality.

“Alright, let’s go—”

He embarked on his third trip to the other world.

———

He happened to reappear near Todd Village. Time hadn't advanced due to the transfer, and the night sky was still visible. The villagers were asleep.

“That’s right, I have to be the bodyguard for this village. Guess I’ll be starting right away.”

Knowing that he wouldn't be able to sleep if he went back to the house, Shoot left the village. He planned to return in the morning and decided to explore the other world at night.

Although the stars provided some illumination, it was still dark and his vision was poor. Shoot used his fire magic to light his way.

Initially, he enjoyed the improved visibility, but using magic continuously depleted his stamina.

“This feels like a marathon… (huff, huff) I can’t use it for too long…”

Giving up on the light, he walked through the dark grassland for fifteen minutes until he entered a forest he'd visited before. It was even darker inside, and he decided not to go any further.

As he was leaving the forest, Shoot encountered the kind of battle he’d been hoping for. It was a group of goblins, but one of them was different.

“That larger goblin is a Hobgoblin… a higher-level goblin monster.”

Hobgoblins possessed the strength of four or five goblins and had relatively high intelligence. They often traveled in pairs or threes, or led groups of goblins. This Hobgoblin had a rusty sword and, upon seeing Shoot, aimed it at him with killing intent.

“Alright. My first battle with this improved body!”

Feeling excited about his new weapon, Shoot drew his sword to face the Hobgoblin. He met the Hobgoblin's attack head-on, his superior strength already evident, and disrupted the Hobgoblin’s balance.

“RAAH!!”

SLASH!!

With a single strike across the Hobgoblin’s chest and stomach, he neatly cleaved it in two, killing it instantly.

“Wow… My sword feels lighter than yesterday, and I feel stronger…!”

Hobgoblins were as strong as Blood Wolves, difficult for even intermediate-level warriors to kill in one hit. Shoot's strength had already reached that of an advanced warrior.

After quickly eliminating the remaining goblins and gathering the materials, Shoot was about to leave the forest when he sensed a new threat.

“Something… powerful is coming…”

The sound of snapping branches and heavy footsteps approached. The monster was…

“…”

Even larger than the Hobgoblin.

Author's Note

This is roughly the latter half of the prologue.