CHAPTER 20 — The Heat of Progress
(18 April, S.C. 1510)
Morning sunlight broke through the clouds as Ren crouched beside his clay furnace, poking the dying embers with a stick. The furnace worked, yes — it changed the color of iron ore, it heated evenly — but not nearly enough.
Ren frowned.
"I need more heat. Much more."
Kiro sat on a log eating an apple. "Maybe hit it harder?"
Ren sighed. "Heat, not violence."
Luffy ran in circles screaming, "I CAN MAKE HEAT WITH MY MOUTH!! FWOOOOO!!!"
He blew air at the furnace, almost falling face-first into it.
Ren grabbed him by the shirt. "Stop. You'll burn your face."
"I WANNA BE FIRE!!"
"You can't."
"WHY??"
"Because you're five."
Luffy gasped. "THAT IS TRUE!"
Ren buried his face in his hands.
---
PART 1 — AIRFLOW EXPERIMENTS BEGIN
Ren poked the furnace again.
"Fire needs three things: fuel, heat… and oxygen."
Kiro nodded, pretending to understand. "Yes. Obviously. Oxygen."
"You don't know what oxygen is."
"No idea."
Ren continued.
"If I can add air to the fire faster, the temperature will rise."
Luffy shouted, "I CAN ADD AIR!!!"
Before Ren could stop him—
Luffy inhaled deeply…
Then blew into the furnace as hard as he could.
FWOOSH!
The fire exploded upward.
Kiro fell backward screaming.
Ren's hair stood straight up.
Luffy cheered.
"REN! DID YOU SEE THAT?! I MADE A BIG FIRE!!"
Makino sprinted over with a bucket.
"LUFFY!!"
She dumped the water on him — and Ren.
Ren sat dripping.
Luffy giggled.
Kiro laughed uncontrollably.
Makino glared. "Ren, what did I say about explosions?"
Ren coughed. "…No explosions."
"Exactly."
---
PART 2 — THE FIRST BELLOWS (Primitive Version)
That night, Ren sat staring at the furnace.
"If blowing increases heat… then I need something that blows a lot of air."
Kiro blinked. "A giant person?"
Ren sighed. "No. A tool."
He gathered:
two flat wooden boards
cloth scraps
rope
glue (drying powder + water)
two bamboo tubes
He explained as he worked:
"These boards will act like sides.
The cloth forms a bag.
The bamboo tubes let air out in one direction."
Kiro frowned. "Ren… are you making a weird pillow?"
Ren grinned. "No. A bellows."
Luffy watched, mouth full of berries. "WHAT'S A BELLS?"
"Bellows. A tool for blowing air."
"THAT'S ME!!"
"No. This is better than you."
Luffy gasped in betrayal. "NOTHING IS BETTER THAN ME!!!"
Ren ignored him.
After an hour, the bellows was assembled.
Ren squeezed it—
WHOOSH
A strong jet of air shot out.
Kiro jumped. "WOAH!"
Ren smiled. "Perfect."
---
PART 3 — THE FURNACE UPGRADE
Ren placed the bellows near the furnace's air intake.
He lit the fire.
Then pumped.
WHOOSH
WHOOSH
WHOOSH
The flames shot higher, brighter, hotter.
Ren shielded his eyes.
"This… this is what I needed."
The temperature nearly doubled.
The crushed iron ore glowed faintly red at the edges.
Kiro whistled. "That looks dangerous."
Makino, appearing behind them, whispered nervously, "Ren… don't burn the forest."
Ren pumped one more time.
WHOOSH
The fire roared like a small beast.
Luffy clapped. "REN HAS MADE A FIRE MONSTER!!"
Ren puffed up proudly.
"…It's science."
---
PART 4 — SALT PRODUCTION GOES BIG
By afternoon, Ren returned to the beach with Makino, Kiro, and Luffy carrying three new large clay basins.
Yesterday he made a handful of salt.
Today he wanted production.
He arranged:
6 clay basins in the sun
2 wooden stands
1 barrel for collected seawater
Makino raised a brow. "Ren… this looks like a business."
Ren nodded. "I want to sell salt to traveling merchants."
Kiro blinked. "You're… thinking big."
Ren looked at the sea.
"I don't want to rely on luck.
Or charity.
Or survival instincts."
He touched one of the basins.
"Money means I can build a real lab someday.
Tools.
Materials.
Books."
Makino's eyes softened.
"You're growing up fast."
Luffy shouted, "I WANT TO GROW UP FAST TOO!!"
"You need to drink milk," Makino said.
"NOOO!!!"
---
How Ren Scaled Production
Ren taught Kiro how to:
scoop seawater
fill basins evenly
filter floating debris
scrape salt crystals safely
He even assigned simple tasks to Luffy:
"Luffy, your job is to scare the seagulls away."
"OKAY!!!"
Luffy ran around shouting at birds.
Kiro wiped sweat. "He's… surprisingly good at this."
Ren nodded. "Luffy has unlimited stamina. It's useful."
Makino added, "If only it came with unlimited sense."
---
RESULTS
By the end of the day—
Each basin produced a small handful of clean, white crystals.
Together?
A full bowl of salt.
Ren held it in his hands.
His eyes sparkled.
"This… is value."
Makino smiled warmly. "Ren, you're creating something wonderful."
Kiro clapped him on the back. "Next step — merchants?"
"Yes," Ren nodded. "Tomorrow I talk to them."
Luffy grabbed a pinch of salt.
"IT'S SNOW!"
Ren shouted, "DON'T EAT THAT—"
Luffy ate it anyway.
"BLEAAAAAHH IT'S BAD SNOW!"
Ren sighed. "This is exactly what I expected."
Makino giggled.
---
PART 5 — Nightfall: A Scientist's Growth
Ren returned to his shed, opened his notebook, and wrote:
> Salt:
✓ Small-scale → successful
✓ Medium-scale → successful
→ Next: sell to merchants
Furnace:
✓ Bellows increases heat
✓ Ore reacting more
→ Next: design better airflow + deeper furnace
Fishing:
✓ Improved traps
→ Sell to fishermen soon
Goal:
Build tools
Understand materials
Earn money
Improve science
Grow at my own pace
Ren smiled softly as he closed the book.
Today felt like a true step forward.
Slow, steady, meaningful progress.
The kind of progress that built civilizations.
The kind of progress that made scientists.
And Ren whispered before bed:
"Tomorrow… I start my first real business."
---
End of Chapter 20