While Jin began to think about the concept of a flying golem, Erza and Saki also began to work on a new project. <.

The term "blood products" in modern Japan is a generic term for medicines made mainly from human blood, and does not include the blood of demons.

However, since there are no demons on earth to begin with, Erza uses this term knowing the original meaning of the term and assuming that there is no problem in using it in Ars.

In other words, it is a medicine made from .

"I see. <. Sounds interesting.

"I knew Saki would say so."

So they immediately started their experiments.

"Is Erza still working on this at all?"

"Yes, she did on some of the demons.

At that time, Erza's research targets were <> and <>.

As for the <>, the healing magic was put into the <>, and it was exported to the > as a recovery medicine.

"But since they could not be hunted regularly, there was no stable supply. That's why it was never established as an industry, I guess."

"The blood of the Death Serpent has been preserved, though.

Collecting materials and making specimens is also one of Saki's specialties.

"<>, <>, <>, and <>."

They are stored in the <> so that they can maintain their quality semi-permanently.

Using them, he said, "Let's examine them again.

* * * * * *

These fluids contain common components that can be classified as , Saki said.

"Red blood cells, white blood cells, and platelets.

Saki said as she showed the centrifuged blood sample.

Since there is no anticoagulant in the blood, the separated components can be considered as serum.

As a side note, centrifuged blood mixed with anticoagulant is called plasma.

"So I can centrifuge this serum at subsonic speed, right?"

"Uh-huh."

In the beginning, the separation was done by Reiko's swinging, but now there is a special centrifugal separator.

It is a subsonic centrifuge that rotates at 200,000 rpm.

With this, we should be able to centrifuge the samples for five minutes."

"Be careful, Saki."

The subsonic speed makes it dangerous if the sample is ejected or the machine is damaged.

Therefore, the body of the centrifuge is made of 64 light silver and is magically reinforced during operation.

And the adamantite exterior is double-layered, with a fail-safe that prevents the centrifuge from being turned unless both lids are closed.

"Yeah, I'm careful."

Saki sets the device with a careful hand, a far cry from the roughness of his daily life. Her appearance was completely safe.

Erza felt at ease and let her do the work.

Five minutes later, the drive stopped, but the centrifuge, which had been spinning with inertia, did not stop until two minutes later.

"Is it done?"

Saki opened the lid of the subsonic centrifuge with joy.

"Oh, it's separating properly. ...... Elsa, please."

The blood was separated into a reddish-brown blood clot, a yellowish serum, and a clear .

"Hmm. ......<>"

Elsa checks each component.

"There is a good separation between the clots, serum, and the true serum. The only question is what grade is the true serum.

"Oh, but it's still a true serum, isn't it?"

Although the Death Serpent is considered inferior to dragons as a demon, it is quite fortuitous that it was able to obtain the true serum.

"Now, let's take out only this true serum from ......."

Saki transfers the true serum into a beaker using a dropper.

"This is then filtered ......."

The true serum is filtered through a filter paper made of fine-mesh Japanese paper. By repeating this process three times, even the slightest remaining impurities are removed.

This process produces about 20 milliliters of the true serum derived from the Death Serpent.

Once this has been obtained, it is placed in an airtight container and stored in an <>.

The same procedure was then used to process the blood of the <>, and about 25 milliliters of the true serum was obtained.

After extracting the true serum from the <, the experiment enters the second stage.

The second stage of the experiment is to find out how much difference there is in each of the true sera.

"Kuhu, this is exciting!

Saki was enthusiastic, but Erza told her calmly.

"Saki, let's wash our hands and have lunch.

"Yeah. ...... just a little bit more. Just a little bit more."

But Erza shakes her head.

"No. Saki said so and skipped the meal.

And then he comes in,

"Saki-sama, Erza-sama, your meal is ready.

"Saki-sama, Elsa-sama, your meal is ready.

"Come on, Saki. ......<"

After cleaning themselves and their clothes and washing their hands, they go to the dining room.

There sat Jin and Reinhardt.

"Hi Elsa, Saki.

"Brother Rai, you're back?"

"Yeah, yeah, just now."

Reinhardt had gone on a trip to Shoro, hiding his real name.

"Some things have changed, some things have stayed the same.

Over dinner together, Reinhardt tells a story that also serves as a report.

Four hundred years ago, Reinhardt had been a diplomat for a while and had visited many places in Japan and abroad.

"Elsa's uncle used to be a lord of Lake Wass. Now it's a busy place with a harbor."

"...... Uncle Burroughs' estate?"

Burroughs Richter von Arabus. Elsa's foster mother and Marlene's brother.

He was a viscount and lord of the Wass Lake area.

He was childless, and though not related to Elsa by blood, he was very fond of her.

Later, he adopted a son to take over his lands.

"I suppose that since the Richter family still rules today, they have made it all the way to the present time without much trouble."

I hope so.

Jin could not interfere in this area, so he asked Saki about it.

"So, how is your research going?"

"Yes, it's going well. I wanted to keep going a little longer, but Erza said I had to eat. ......

"That's right."

Jin puts himself on the shelf and lectures Saki.

"Saki, you always prioritize your research even if it means cutting back on food and sleep, don't you?　And you don't even care about your clothes and personal appearance.

"Kuhu, it hurts my ears, but I think Jin is pretty much the same in that respect.

"...... Ah, ah. So lately I've been listening to the advice of Erza and Reiko.

"Is that something you can be proud of,......?"

"Ah,ah,ah,ah,ah,ah,ah,ah,ah,ah,ah,ah,ah,ah,......

The spring breeze blew gently and the sea was calm.

The island of Horai was peaceful.