Fire. Water. Earth. Air.

"What is a magic structure?"

        Manabu turned from the blackboard, his chalk-stained fingers tapping lazily against his palm as his gaze settled on the only two students present. Mikado and Kakeru sat several desks apart in the otherwise empty classroom. They exchanged a brief look, not the look of students who didn't know the answer, but of people genuinely puzzled as to why such an elementary question had even been asked.

        "I know, I know," Manabu said with a weary sigh before either of them could speak, lifting a hand in surrender. His necktie hung loose, and his unkempt hair looked like it hadn't met a comb since yesterday, if at all. "You're probably thinking, 'Why is he asking this damn basic stuff?'"

        He turned his back to them again and scrawled magic structure across the board in the uneven letters.

        "But I can't be blamed for going back to the basics," he continued. "You have a written test coming up, and whether you like it or not…” He glanced over his shoulder, eyes half-lidded with exhaustion. "…the two of you are close to the bottom."

        Manabu let out a dry chuckle.

        "And as your homeroom teacher, your failures don't just stay yours," he said, rubbing his forehead. "They crawl right up and bite me in the evaluation. So humor me."

        The chalk paused mid-air.

        "Now," he said, turning back to face them, "what is a magic structure?"  

        Manabu straightened his back, chest rising with a small puff of pride. "Magic structures are the deciding factor in whether someone becomes a mage, and they're what allow people to use magic," he said, his fingers tracing invisible lines in the air as if conducting unseen energy. "Think of them as rivers of mana flowing through a mage's body—spiritual organs that act like an internal pseudo-nervous system, carrying your will and shaping it into mana. Each mage's magic structure has six levels, and each level is like a wider, stronger river, capable of carrying more power. Every mage begins at level one, where the streams are narrow and fragile, and grows stronger as they train, learn, and refine their craft. The higher your magic structure level, the greater your command over these rivers of energy, and the stronger your magic becomes."     

        He paused to let the words settle, adjusting his tie with a quick tug as his gaze swept the room, landing briefly on each of the two students.

        "Which you failures shouldn't even hope to cross paths with," Manabu added, letting a sly, mocking grin curl at the edge of his lips. He tapped the chalk against the board again, spinning it between his fingers with a casual flick, drawing their eyes like a predator to its prey.

        "In that sense, level-up talent applies to that too," Kakeru muttered, his shoulders slumping slightly as he scuffed his shoe against the floor.

        Manabu's grin softened just a fraction, tinged with a hint of resignation. "Well, that can't be helped. There are people born with natural talent in magic—those who will leave you in the dust no matter how much you grind your bones and train."

        He turned back to the board, chalk scratching a fresh line across the black surface, a subtle sigh escaping his lips as if lamenting the futility of trying to teach the hopeless.   

        "Anyway, back to the topic," Manabu said. "A magic structure awakens within a mage at around the age of ten—though that age can vary. Talent, as you mentioned, plays a role."

        He gestured toward Kakeru.

        "And in this magic-oriented world, two major factors define a mage after awakening: the elements they specialize in, and the two uses of magic—Invocation and Amplification."

        He tapped the board once more.

        "Let's start with elements." Manabu turned back to the board and began writing, the chalk scraping loudly as fine white dust rained down with every careless stroke.

        Fire.

        Water.

        Earth.

        Air.

        He stepped aside, letting the words sit there in stark contrast against the black surface.

        "The four basics," he said. "The ones even a kid who just awakened yesterday knows."

        He glanced back at Mikado and Kakeru, eyes narrowing slightly.

        "Now, every mage has one base element they excel at—an affinity. It's the element your mana responds to best, the one you can shape with the least resistance. That's what makes a mage exceptionally good at one thing while merely decent at the rest."

        He lifted the chalk again, tapping lightly beneath Fire.

        "Don't misunderstand. Having an affinity doesn't mean you're forbidden from using other elements. A fire mage can learn water spells. An earth mage can manipulate air. Magic isn't that narrow."

        The chalk paused.

        "But those spells will always feel… heavier. Slower. Less obedient."   

        "And while I've only listed these four as the base elements," Manabu continued, tapping the chalk against the board, “there exists another factor—Advanced Elements.”

        He underlined the word once, firmly.

        "As the name suggests, they are higher, more refined expressions of the basics. Variations born from deeper mana control and altered affinities. Take water, for example. Push it beyond its natural state, twist its properties, and you get things like ice, mist… or poison."

        Having arrived at school nearly two hours early, Mikado couldn't stop a yawn from slipping past his lips. His eyelids felt heavy, his body begging him to rest. And yet, despite the drowsiness, he kept listening.

         No matter how many times he heard it, he couldn't help himself.  There was something captivating about the origins of magic, about hearing how simple elements evolved into something far more dangerous and profound.

        "—That covers the entirety of elements," Manabu said, tapping the chalk against the board once again. "So now, we move on to the two uses of magic: Invocation and Amplification."

        He glanced over his shoulder at the class.

        "The names are pretty self-explanatory, but humor me."
He underlined the first word.

        "Invocation is the act of projecting magic outward, using mana to directly influence the world. Conjuring fire. Raising walls of earth. Shattering the ground beneath your enemy's feet.”

        The chalk slid down to the second word.

        "Amplification, by contrast, is an internal application of magic. It enhances the user's own body, strength, speed, agility, and even perception. When properly executed, an amplified body can move faster than the eye can track, generate enough force to fracture steel, and deflect bullets with bare hands."

        He paused, letting the distinction sink in.

        "Same mana. Two completely different philosophies."  

        "The clearest example of this," Manabu continued, scratching the back of his head as he searched for a name—someone who would make the lesson not just profound, but relatable—

        "—the Fire Empress," Mikado cut in.

        Manabu blinked, his train of thought derailed. Turning his head, he caught Kakeru grinning at Mikado from the corner of his eye. Mikado scowled, his eyebrows knitting together.

        …What is this guy's deal?

        The teacher had barely finished thinking of an example, and Mikado had already named one, as if he'd been waiting for it. Manabu sighed inwardly. At least they were paying attention… even if it was in their own irritating way, he thought. 

        "Right. The student council president is the perfect example of someone who embodies both approaches."

        Manabu raised his chalk and pointed it toward the board, as if the name alone carried weight.

        "Eto Morioka, more widely known by her nickname, the Fire Empress—possesses fire as her primary affinity. Through magic invocation, she externalizes her mana, shaping it into tangible destruction. Her most infamous technique is the creation of fire meteorites."

        He let that sit for a moment.

        "And if I'm being honest," he added, voice flat, "that alone makes her far too dangerous for the average maggot to even think about provoking."

        A few students shifted uneasily in their seats.

        "But invocation is only half of her strength," Manabu continued. "Her true terror lies in magic amplification."

        He tapped his own temple.

        "Instead of casting fire outward, she feeds it back into herself. She uses flame to heighten her senses—to feel fluctuations in ambient heat, detect movement through thermal distortion, and read her  surroundings as if the world itself were burning in her awareness."

        Manabu turned back to face them.

        "Same mana," he said. "Same element. Two completely different philosophies—and Eto Morioka has mastered both." Manabu let out a low breath, almost reverent. "That alone makes her one of the very few Level Six mages in Second Shibuya—no," he corrected himself, a faint grin tugging at his lips, "probably in the entire world."

        By the end of it, Manabu sounded less like a teacher and more like a devoted fanatic. Mikado couldn't help but glance sideways. Kakeru was beside him, gripping the edge of his desk and dragging it closer with an exaggerated scrape, as if proximity alone might grant him better gossip reception.

        "Hey, Mikado," Kakeru whispered, leaning over conspiratorially.         "Forgot to tell you earlier—there're exchange students arriving today. From Europe."

        "Is that so?" Mikado replied, genuine curiosity flickering in his voice. The topic caught his attention.

        Kakeru grinned, lowering his voice even further, as if sharing a classified secret.

        "—and it's a girl. Heard she's pretty beautiful, too."    

        "For God's sake, you two—listen here!" Manabu's voice exploded through the classroom like a thunderclap. From an outsider's perspective, one might have wondered how a man lecturing to only two students could project such a deafening roar—but that was a question best left for another time.