CHAPTER 19 — The Furnace in the Forest
📅 17 April, S.C. 1510
👦 Ren — 7
👦 Luffy — 5
👦 Kiro — 7–8
📍 Windmill Village → Forest Edge
The morning breeze was cool and crisp as Ren sat cross-legged on the floor of his shed, surrounded by drawings, notes, clay cups, sticks, and leftover fish-trap pieces.
Yesterday's success still buzzed in his veins.
Filtered water — sold.
Sealing paste — sold.
Healing gel — sold.
Fish trap — worked perfectly.
Salt — profitable.
He wasn't just experimenting anymore.
He was building something.
Ren took a deep breath and whispered to himself:
"Time to move forward."
PART 1 — SALT: FROM DISCOVERY TO PRODUCTION
Ren walked to the beach carrying:
3 clay basins
1 wooden scoop
a notebook
an excited Luffy
a skeptical Kiro
Luffy raised both hands.
"WHAT ARE WE DOING?!"
Ren answered calmly. "Salt production."
"CAN I EAT IT?!"
Kiro muttered, "He's five, Ren. This is his entire personality."
Ren positioned the three basins on a flat rock.
"We fill these with seawater," he explained, scooping water until the basins were full.
"The sun will evaporate the water and leave salt behind."
Kiro blinked. "So it's like… drying soup?"
Ren smiled. "Yes. But the only flavor left is salt."
Luffy gasped. "SOUP SALT!!"
Ren's face dropped. "…No."
Makino approached with a basket. "Ren, this is smart. If you can scale this up, you can supply the whole village."
Ren nodded. "That's the plan."
Kiro gave him a teasing smirk. "Look at you. Little businessman."
Ren blushed. "It's just… science."
Makino corrected softly, "It's effort. That's what matters."
Ren looked down shyly.
PART 2 — IMPROVED FISHING TRAPS
Ren crouched beside yesterday's trap and examined the bamboo funnel.
"It caught fish, but not efficiently," he murmured.
"How do we fix it?" Kiro asked.
Ren pointed.
"Make the funnel narrower. Fish enter easily but can't turn around."
Kiro nodded.
"And the bait container should be sealed except for tiny holes — the smell escapes, but fish can't steal the bait."
Luffy held up a worm.
"This worm can go inside the trap!"
Ren shook his head. "Too big."
"TOO BIG FOR THE TRAP?!"
"No, too big for your brain."
Makino yelled from the distance, "Ren!"
Ren corrected himself, "I mean—too precious to lose."
Luffy hugged the worm lovingly. "I WILL PROTECT YOU."
Kiro whispered, "Ren… you created a monster."
Ren sighed deeply.
They worked together:
Kiro cut bamboo into finer strips
Ren tied stronger funnel angles
Luffy tested the "fish smell spread" by waving bait everywhere (which scared half the birds)
Within an hour, the new trap looked sturdier, lighter, and more efficient.
Ren placed it into the water.
Minutes passed…
Then they pulled it up.
Five fish.
Kiro whistled. "Ren… this is incredible."
Luffy puffed his chest. "I HELPED!!"
Ren smiled at him. "Yes, Luffy. You did."
Makino, watching from afar, smiled softly.
PART 3 — CLAY FURNACE: THE SCIENTIST'S DREAM
Later that afternoon, Ren carried clay, stones, and logs into the forest.
Kiro followed.
"What are you doing now?"
"Making a furnace."
Kiro blinked. "For cooking?"
Ren shook his head. "For metal."
"You're making metal?"
"No — extracting it."
Kiro stared. "But we already have metal. Blacksmiths have it. The village has tools. Why struggle so much to make something that already exists?"
Ren stopped working.
He stood quietly for a moment.
Then he spoke — not loudly, but with a steady conviction.
"Because I need to understand it.
Not buy it.
Not copy it.
Not take it."
He placed a hand gently on the iron ore in his bag.
"I want to know how things are made. How they change. How they react.
If I understand that…
I can build anything."
Kiro's expression softened.
"You really are different, Ren."
Ren smiled faintly.
"Maybe."
Building the Furnace
Ren shaped the clay into:
a round base
a cylindrical wall
air holes
a small chimney
and an opening for adding charcoal
Kiro helped smooth the edges.
Luffy carried sticks…
then dropped all the sticks…
then carried random rocks instead.
Makino arrived with a basket of fruit.
She stared at the clay structure.
"…Ren. This looks like something out of a history book."
Ren shrugged modestly. "It's just a clay furnace."
Makino smiled. "Just? You're seven."
Kiro laughed. "Yeah, Ren. Normal seven-year-olds draw frogs."
"I can draw frogs too," Ren argued.
Luffy screamed, "I FOUND A FROG!!!"
Makino sighed. "Ren, I need you to teach him science slowly."
Ren: "…I'll try."
Testing the Furnace
Ren placed:
charcoal
crushed iron ore
small sticks
dried moss (for easier ignition)
Then he lit the fire.
The furnace glowed inside.
Heat rose.
Air flowed through the holes.
The flame burned hotter than any campfire Ren had made before.
Not enough to smelt pure metal—
but enough to change the color of iron ore.
Enough to start.
Kiro stepped back. "Ren… this is impressive."
Makino smiled softly. "You're building your own world."
Ren swallowed, touched deeply.
"…I want to understand everything."
"And you will," Makino said.
Ren stared at the glowing furnace.
This was only the beginning.
Nightfall — A New Direction
Back in his shed, Ren wrote in his notebook:
✓ Salt production → expand to multiple basins
✓ Fish traps → improved funnel and bait design
✓ Clay furnace → works, needs higher temperature
✓ Why do this? → Because learning matters
Long-term Goal: Build tools & materials myself.
Understand this world from the ground up.
"This is science."
"This is my future."
Ren closed his notebook gently.
He felt something new inside him —
Ambition. But peaceful.
Curiosity, not greed.
Discovery, not power.
This world was full of mysteries.
And Ren was determined to uncover them —
one invention at a time.
End of Chapter 19