Time always elapses at a speed that makes everyone want to desperately hold on.
Unconsciously, twelve years have passed.
During these twelve years, Itogami Island, as usual, stands on the ocean, presenting itself as an advanced academic city. With ongoing research on demons, technology has been advancing rapidly.
It's truly an incredible world, blending high mystery with advanced technology, unlike any world in the past.
However, due to its location in the Pacific, the temperature on the island remains high throughout the year, never dropping below twenty degrees. This makes life here described as nothing but painful for many who struggle with the relentless heat.
For instance...
"It's so hot..."
In a simple room on the top floor of a luxury apartment, a young boy lies on the bed, staring at the ceiling with an expression that suggests he's contemplating death.
The boy is around twelve or thirteen, with a face full of innocence yet not lacking in charm. He possesses a blend of Eastern and Western features, making him quite handsome—a type that would surely be popular among girls at school.
This boy is none other than Rozen.
"I can't take it anymore..."
Rozen turns over, extending a hand toward a remote control on the bedside table, resembling someone on the brink of death reaching for salvation.
That's the remote control for the air conditioner.
Rozen can't endure the heat inside anymore and is ready to turn on the air conditioning. In fact, with the weather this hot and living on the top floor of an apartment, Rozen could have turned on the air conditioning long ago.
But...
"Swoosh!"
The moment Rozen's hand touches the air conditioner's remote, it vanishes as if it has merged with space, like a mirage, disappearing.
Seeing this, Rozen's face turns into a bitter expression. He doesn't show any surprise at the scene before him but rather looks as if he expected this outcome. He turns his head wearily to look at the bedside.
There, a petite figure has appeared at some point.
"If I remember correctly, I told you not to use the air conditioner for some time, right, Nichiyo?"
A somewhat unclear but authoritative voice comes from the owner of the petite figure.
Upon closer inspection, it's a young girl with long, black hair flowing down to her waist.
The girl's facial features and figure appear very young, with an appearance so refined that one might mistake her for an exquisite doll.
Indeed, it's Minamiya Natsuki.
Twelve years later, Natsuki, who should now be twenty-two, still looks as young and tender as she did back then, wearing a luxurious red and black gown instead of a school uniform. She looks like a child dressed up as an adult, contradictory yet imposing. Her eyes also exude a considerable amount of pressure, a paradox.
But despite her seemingly conflicting appearance, this girl is not only a graduate but also a teacher.
Yes, a teacher.
Natsuki is now a faculty member, an English teacher at a school called Saikai Academy, and seemingly quite popular.
Of course, being a teacher is just Natsuki's overt position.
In reality, as a pure-blood witch, Natsuki has officially joined the management of Itogami Island and currently serves as a national attack mage.
The term "attack mage" refers to those with means to confront demons, such as mages, esper, and others who possess unique abilities to combat demons.
They could be soldiers, members of special forces, employees of private security companies, or mercenaries employed by various organizations. Based on the power systems they use, they have various identities.
However, regardless of the type, attack mages are humanity's existence to confront demons.
For ordinary humans, demons are akin to monsters. Without attack mages, humanity might be completely unable to resist demons, making demons a synonym for terror.
Therefore, attack mages are considered specialized enemies of demons. Some attack mages make a living by hunting demons, living up to the literal meaning of their title—experts in the field of demon combat.
After graduation, Natsuki obtained the qualification of a professional attack mage. In addition to her role as an English teacher, she assumed the position of the national attack mage in Itogami City, also serving as the instructing officer of the special district security team.
She once actively operated in Europe, slaughtering countless demon criminals, instilling fear in European demons. Her strength is among the top tier worldwide among all humans.
Due to her exceptional proficiency in space manipulation magic, effortlessly using the highest-level magic like breathing, she is referred to by the world as the "Witch of the Void."
At the same time, this renowned witch is Rozen's sister in this world, the one who nurtured him to grow up.
So...
"Natsuki-nee."
Rozen gazes at this sister who, despite being ten years older than him in terms of body age, looks almost the same age. In fact, she appears even younger than him, and he opens his mouth with a bitter expression.
"In this kind of weather, it's unreasonable not to let me use the air conditioner, right?"
Rozen is already feeling breathless due to the heat.
In response, Natsuki coldly snorts.
"Using the air conditioner too much can lead to air conditioning sickness. I've told you many times, and since you don't listen, I have no choice but to forcibly prohibit you from using it."
This sister, who looks excessively young, reveals a stern side that doesn't match her appearance.
Although she is a national attack mage and also an instructor for the special district security team, for some reason, Natsuki places great importance on taking up the role of a teacher. She believes that being a teacher is her true calling.
Thanks to this, Rozen has been strictly educated by his sister from childhood. From daily activities to noble etiquette, this sister has taught Rozen almost everything she knows. As a result, Rozen has lived up to expectations, consistently ranking first in the academy, never surpassed by others.
Of course, Rozen is naturally intelligent, and Natsuki's guidance, for him, is at best enlightening and not something he can't handle.
However, not only in terms of grades, but Natsuki also manages Rozen's daily life very strictly. Anything related to Rozen has to go through her rigorous arrangements, even having curfews, making Rozen go through a lot.
By the way, in the industry, Natsuki is also well-known for being a devoted sister, or you could say she has a brother complex.
Perhaps, this is the biggest change that Rozen brought to Natsuki?
"Natsuki-nee..."
Rozen moans, lying on the bed.
"Alright, since you're awake, get up. What's good in lying like that?"
Natsuki furrows her brows, taps Rozen's head, then turns around, leaving the room.
Rozen can only sigh and reluctantly get up.