The maid squad is too strong, what use is there for me, the Demon King?

"What are you thinking?"

"Why do you think apples fall from trees?"

???

For a moment, Gray seemed to see a blue head spinning and flashing, with various numerical formulas constantly emerging around it.

From the single-celled organism Paramecium to the cosmos.

Born by my mother!

Wow, you got hit by an apple just like that great scientist?

Suddenly, Gray seemed to sense a mysterious aura emanating from the girl.

If I had to describe it, it would be the feeling of a female researcher who wears glasses and is completely absorbed in scientific research.

Gray smiled faintly, grabbed the girl, and instantly refined her... cough cough, wrong channel.

Then you've asked the right person.

The existence of fantastical things like magic and sorcery in this world has ironically led to a lack of research into scientific aspects such as physics and chemistry among its people.

Therefore, no one can answer questions like why apples fall from trees.

I, Gray, am a noble reincarnated being, a protagonist-like existence (my Demon King identity gives me a bit of a villainous feel), so answering this kind of question is naturally a piece of cake for me.

The most useful episode of nine-year compulsory education.

Gray paused, cleared his throat, and said, "Because of gravity."

"gravity?"

The appearance of this novel word quickly piqued the girl's curiosity.

The girl looked focused, waiting for Gray to continue his explanation.

Gray smiled inwardly; finally, he had a chance to use his knowledge from his past life. He then said seriously:

Gravity is one of the most fundamental forces in nature.

The basic definition of gravity is the natural force that attracts objects with mass to each other.

However, the attraction between objects is so small that we cannot perceive it.

However, the planet's gravity is still quite noticeable to us.

When you jump up, you will be subjected to a downward force due to the planet's gravity, eventually causing you to fall to the ground.

This works on the same principle as an apple falling.

Gray explained the concept of gravity to the girl in a simple way. He noticed a hint of doubt on her face, but she listened attentively to his explanation, which pleased him.

"Question: What is a planet?"

A thirst for knowledge shone in the girl's eyes; her brows were slightly raised, as if she were trying to catch every possible detail. A gentle smile played on her lips, revealing a curiosity and anticipation for the unknown world. She rested her chin on her hands, gazing intently at Gray, as if trying to extract the essence of wisdom from his words.

It's clear that this girl is very eager to learn. Instead of giving up asking questions because she didn't understand some of the things Grey said, she kept asking about the concepts she didn't understand.

"The world we live in is a planet. We probably call it a plane here; it's the same thing, just a different name."

“Planet…” Gray had barely finished speaking when he saw the girl pondering those two words, her face lighting up with excitement as she asked him:

"If it's called a planet, then that means the world we live in is round, right?"

Gray nodded, then heard the girl murmur to herself:

“I told you it was round, but the adults didn’t believe me. They said I was joking and insisted that the world is square.”

Gray had originally planned to give the girl some examples of how the world is round, but he didn't expect that the girl already knew that the world is round, a concept that was ahead of everyone else in the other world.

The girl looked at Gray, and their eyes met. Gray felt the intensity in her gaze.

"Please teach me more, teacher!"

They're calling him "teacher" right now? Their thirst for knowledge is truly strong.

Gray gave a smug snort, his eyes seemingly gleaming with wisdom.

"Then you'd better listen carefully, I'll teach you a mnemonic." Gray looked at the serious girl and couldn't help but tease her a little.

The girl leaned forward slightly, closing the distance between herself and Gray, adopting an attitude of attentive listening.

Gray took a deep breath.

"Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Sodium, Magnesium, Aluminum, Silicon, Phosphorus, Sulfur, Chlorine, Argon, Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Gallium, Germanium, Kun (Arsenic), Selenium, Bro

It flowed smoothly and effortlessly, but unfortunately, Gray only remembered the first 36 elements of the periodic table and couldn't recall the rest.

Now it was the girl's turn to be bewildered.

Born by my mother!

what?

Looking at the girl's blank expression, Gray chuckled and said, "Don't understand? That's normal. This is advanced knowledge. I can teach you some basic math first, and then move on to physics and chemistry."

No Li? Huaxue? What are these things?

But this did not dampen the girl's thirst for knowledge; she immediately raised her hand:

"Teacher, I've already mastered math, so you can teach me other things now."

Upon hearing this, Gray shook his index finger.

What is mathematics in your eyes?

"Isn't it just addition, subtraction, multiplication, and division?" the girl replied.

"Naive!" Gray shouted, but the girl was not frightened by the sudden action.

I don't know if it's because of their boldness or their strong thirst for knowledge that it has overwhelmed everything else.

"Mathematics is endless! Do you know about powers? Do you know about unknowns? Do you know about functions? Do you know how to solve the chicken-and-rabbit problem? Do you know..."

Despite being harshly scolded by Gray, the girl showed no sign of distress or frustration, but instead retorted in a resounding voice:

"Please forgive my ignorance, teacher! I beg you to guide me carefully!"

"いいだろう. (Okay)"

So, during the rest of the holiday, Gray kept teaching the girl new things.

The girl, however, showed no signs of fatigue; instead, her eyes shone as she studied and asked questions one after another.

The girl's eyes, those bright pupils, were like two dazzling stars, searching for their own light in the universe of knowledge. Her pupils dilated and contracted with the content of the conversation, each blink a manifestation of digesting and understanding the information. Her gaze followed Gray's lips intently, afraid of missing a single word.

Her brow furrowed and relaxed at times, reflecting her thought process: confusion, reflection, and understanding. When she encountered concepts that were difficult to understand, she would unconsciously furrow her brow and gently tap her temples with her fingers, as if trying to open the door to knowledge.

Her mouth would occasionally open slightly, as if she were swallowing back the questions that were about to spill out, waiting for the best opportunity to ask. When she finally couldn't help but ask, her voice was gentle yet firm, each question carefully considered, showing her thirst for a deeper understanding of knowledge.

This continued until the maids came looking for him, signaling the end of Gray's free vacation and his need to go back.

The girl looked reluctant to part until Gray whispered something in her ear, at which point her furrowed brows relaxed.

"Can you sneak out tonight? Come to this place, and I'll send someone to pick you up."