Lao Kun was working on the development of the sunscreen that Jin had asked him to make.

Using a mobile terminal < and assisted by <, who can use engineering magic, he conducts experiments by changing the ratio of the ingredients and the size of the light silver oxide particles.

The appearance was to be transparent, but the UV shielding or reflecting effect was to be as large as possible.

We will also consider the composition of the moisturizing oil, whether it should be vegetable, animal, or synthetic oil.

>

However, we can't just go ahead and conduct <, to put it bluntly.

At that time, Saki came to Horai Island. The old man decides to ask Saki for advice.

"What?　Sunscreen?　Can you make such a chemical?　Yes, I will help you!

> present while we inspect you, so we won't do anything that will be a burden on you.

The <> referred to here is a doctor (healer) automata created by Jin.

In the first place, most of the base moisturizing oils are chosen from those already in use in this world, and light silver oxide itself is known to be harmless, so it is unlikely that the combination would be toxic.

"Hmmm...such a combination."

Saki nodded as she looked at the combination on the paper Lao Tzu had spread out.

"As far as I'm concerned, I think it's better to use this one and this one for the oil.

Saki recommended the oil used for chapped and cracked skin in winter.

"I would say the oil of <> and the oil of <>."

> is a specialty of the Kingdom of Klein and has good preservation properties among animal oils.

<<> oil is also used for hair oil and its safety is guaranteed by its long history.

"Yes, that's what I mean."

I am cautious this time, since I once had a lacquer rash.

"Yes, that's right.

After three days of experimentation with Saki's help, the prototype of the was completed.

< the material, no toxins or other harmful or unknown substances were detected, Saki decided to try it on her own arm.

Her curiosity seemed to get the better of her.

However, she proceeded very carefully with the . I left it on for a whole day and had no problems at all.

If itching or redness had occurred, I would have been ready to treat it immediately with , but my fears were unfounded.

"Jin is planning to go to a southern island for our next time, so we can test it then, too.

"Then there is the sales channel, but I think the old man is more qualified for that than I am.

"Oh, I see. Do you think we can wholesale the light silver powder directly from Horai Island?"

"Hmph, you are indeed an old man, I don't think I can take care of that much.

<<< Thank you very much. Thank you very much for your cooperation in the development of ...... Saki.

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

"Kemeria oil, is it?

Licia Faalheit, the lord of Toka Village, pondered for a moment when she received a message from the old man.

It is the end of summer, and the Kemeria berries will be ripe in a few days.

"It's the right time, isn't it? The harvest will start in about a month. We need more people this year.

"Oh, yes. I'm sure Jin-san will make a wonderful tool for you!

Licia's trust in Jin seems to be very strong.

"We still have some Kemeria oil in stock.

<

Wholesale price affects the selling price. If the selling price goes up, the sales will slow down, and as a result, the profit may decrease.

Of course, there are products that are purchased even if the price is high. But in the case of new products, the price you set at the beginning is very important.

The old man explained.

* * * * * * * * * * *

"<>?"

The old man first checks with Eric, the owner of the store in the village of Kaina, to see if he can sell it.

Of course, he has , who works at Nido Castle, as his agent.

"Yes, that's right. ....... I think it could be sold to a nobleman or a wealthy merchant in the capital. I don't think it's likely to be sold in this village. ......"

"I'll buy it, depending on the price."

Before Eric could finish his answer, Barbara quickly interrupted him.

I'm not sure I'm going to be able to sell it in the village. ...... Eric, you do care, don't you?"

"Uh, yes. ......"

"I see, that's very helpful."

* * * *

The "Mere Old Man" immediately makes a plan.

The moisturizing cream was made by Jin for the village of Kaina.

Oil from pressed walnut-like nuts called ornut, a little beeswax from honey, and a little perfumed oil from citran peels.

In addition to these, some Persica juice, which has been <>, is added to the mixture to increase its shelf life.

The mixture is then homogenized by engineering magic.

The old man had found the best ratio by trial and error by changing the ratio of the ingredients.

The combination of this moisturizing cream and sunscreen seems to further enhance the anti-aging effect of the skin.

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

"Oh, so this is sunscreen."

First, as promised, the and were presented to Princess Rieschen. Together, they form a skin care set.

Later, the skin care set was sold through the Raglan Trading Company in Alban, the capital of the Kingdom of Klein, and was a great success.

Since it was sold to the general public as a stand-alone moisturizing cream, the number of people suffering from rough hands and rough skin decreased dramatically.

It did not take long for the product to spread throughout the Kingdom of Klein and even to neighboring countries.

* * * * * * * * * * *

"Kuhu, it's important to take care of your skin.

Saki smiled to herself as she stroked her recently smoothed skin.