After a little early dinner, Jin was leaning back on the sofa, thinking about the daytime.

"Brother Jin?"

Erza seemed to sense something when she saw Jin, and took some distance from him, saying that she would leave him alone.

"Wedge ...... pickaxe ...... drill ......"

The way he mumbled was a little strange, but Erza has long gotten used to the fact that this was Jin's way of thinking.

After about five minutes.

"Okay, I've got a plan. Now we have to ask him.

Jin stood up briskly,

"I'm going to Mii's for a while."

and left the room. In a flash, Reiko was the only one who could follow him, but Elsa only replied with a .

* * * * * * * * * * * *

After about half an hour, Jin came back, his face full of happiness.

"Did something good happen?"

Erza couldn't help but ask him.

"Yes, I did. You know, during the day, there was a big rock that came out during the construction work, right?

"Yes..."

Reiko crushed it that time, but I asked her what she usually does.

hmm, I know...

I asked her about Mr. D'Souza, the foreman, who was staying here earlier.

He said he was staying at the staff building because there was no good place to stay near the construction site.

"Really?"

Jin looked interested, so I knew something must have struck a chord. I didn't think it was civil engineering, though.

"So, when they break it up, they do it with a hammer or a hammer and trowel," he said.

"......What are you going to do with that?"

I'm sure you can guess by the look on her face, but Erza asked just in case.

"Yeah. I'd like to be of some help, wouldn't you?

So Jin then returned to Horai Island.

"If we use adamantite partially, it will be enough.

"Father, what about the rest?"

"Carbon steel ...... or maybe nickel steel?"

"Yes, sir."

With the help of Reiko, Jin made up a pickaxe. The tip is adamantite and bites into most rocks.

The nickel steel has also been treated with toughening, so it should be strong enough.

"Now, let's make a hammer too.

This is also made of adamantite at the tip, and the amount of excavation is estimated to be three times as much.

The last one is .......

A drill?

Yes. I think I heard that you drill a hole with this and then drive a wedge into the hole to break it open.

I see.

Jin is making a hand drill. It is a type of hand drill called a "click-ball" or "kuri kogiri".

The drill is designed to simply turn a crank handle, so it is hard to break.

The tips of the drill bits are of course adamantite.

After making 10 sets of each of these bits, Jin returned to Mitsuho.

Welcome back.

Welcome back.

It is 8:30 p.m. in Mitsuho when Jin returns.

Jin had Reiko take the samples and went to D'Souza's office.

"Jin, what do you have there?"

Jin meets Reinhard and Mii in the hallway. They were discussing tomorrow's schedule.

"Jin, what is it?"

Reinhardt was curious about the tools Reiko was carrying.

"It's a construction tool. This is a pickaxe, this is a hammer, and this is a drill."

"Hmmm. The drill has an interesting shape!

"We're going to Mr. D'Souza's now."

Jin said,

"Okay, I'll go with you!"

Reinhardt's reply was quite natural.

"Mr. D'Souza, are you there?"

Jin asks D'Souza's room in the staff building.

"Oh, my God, Jin-sama, what is it yet?

"I've prepared something nice for you, please take a look."

In the lounge of the staff building, Jin showed Reiko the tools he had prepared for her.

"Well, that looks interesting!

"A hammer, a pickaxe, and a drill."

Jin explained briefly.

"I know what a hammer is, but what about this?

"This is how to use it."

Jin first teaches how to use the pickaxe.

But all he does is swing it up and down.

"Ha-ha, this is good. It seems to be an efficient way to dig up areas with pebbles.

D'Souza, who seemed to be a person in the field, immediately understood the usefulness of the pickaxe.

"And this is a drill.

"A drill?"

"A drill? Well, do you have anything I can use to make a hole?

Mii thought for a moment, then went to the kitchen and came back with a big jar.

"How about this jar?　It has a chipped rim, and I'm thinking of using it as a flowerpot.

"Then I can make a hole in it.

Bottles, or ceramics, are a very hard material.

It is also fragile, so making a hole in it requires not only tools but also a certain amount of skill.

Jin turned the bottle upside down with the bottom facing up. He places the tip of the drill in the center of the bottle and starts to turn it.

"Oh!"

The adamantite tip cut through the ceramic without any effort, and made a hole in no time.

"This is amazing!　That's just like Jin-sama!"

"Jin-sama, will you give this to me?"

Duzah jumped for joy, and Mii's eyes lit up.

"Yes, I will."

"Yes, I will, and I will be very grateful!

Mii then went into a meeting with Jin to discuss the price.

"As far as I'm concerned, it's a token of our friendship, so it should be minimal.

But that's not how it works.

"But ......"

After some back and forth, they agreed to increase the amount of miso and alum that they were going to receive in exchange for <>, and to share some of the wood they saw at the workshop, which was not available on Horai Island.