I bit into a sandwich while skimming the first book.
The text wasn't in Japanese, yet I could understand its content perfectly. The sensation was strange but not unwelcome. I kept reading.
Even if some of the information felt redundant, starting from scratch and organizing the facts was essential.
This world has three major continents.
I currently reside in a country called Magia, located on the smallest of these continents.
From what I can tell, the edges of the map appear connected, as if forming a continuous loop. While this world lacks the concept of outer space, the sun shines during the day, and the stars glitter at night—just like Earth. This strongly suggests the possibility that the world is spherical and orbits a star.
However, I left this conclusion as a possibility.
Earth's history reminds me how slow and grueling the transition from geocentrism to heliocentrism was, not to mention the centuries when people believed the Earth was flat.
This world could very well follow entirely different rules of existence.
Still, there are undeniable similarities. Days are roughly 24 hours, seasons change, and weather patterns such as rain and sunshine exist.
These observations imply that Earth's physical laws are, at least in part, applicable here.
Gravity pulls rain to the ground, sunlight evaporates water into the air, and rainbows form when light refracts through moisture. The fact that I can breathe suggests oxygen exists, meaning atoms and molecules are likely present.
Though scientific advancements are primitive here, the underlying physics may be astonishingly close to Earth's. For now, I assumed this hypothesis to be true.
"This brings me to the single greatest reason why science hasn't flourished in this world," I muttered, pulling a particularly thick book from the stack.
The title read, The Complete History of Magic.
In this world, alongside physical laws, another force reigns supreme: magic.
In fact, magic dominates every aspect of life here. The very fabric of this world's culture assumes that everyone can use magic. (For someone like me, who hasn't displayed even a spark of magic at sixteen, I'm a rare anomaly—one in several hundred thousand.)
Ironically, even I possess mana within me.
Mana flows through everyone, much like blood. It's an inherent energy present in all living things—humans, animals, fish, and even plants. According to this book, mana also resides in the earth, water, and air.
Whether this description is a spiritual metaphor or literal truth remains unclear.
But what if mana is merely a subatomic particle unique to this world? If so, its ubiquitous presence across all matter would make sense.
This could explain why magic exists as a culture and phenomenon—an energy source embedded into the world's very fabric.
"Still, how does it interfere with other physical laws? Mana isn't fire, water, or electricity, yet it creates wildly different outcomes based on personal willpower. Why?"
"Brother, what are you doing?"
"Whoa!"
The sudden voice startled me, nearly causing me to drop the book.
"J-Johan?! That was quick!"
"What are you talking about? It's been five hours since I last saw you! My lesson ran longer than usual," my twelve-year-old brother said, bounding into the room.
"Five hours? I didn't realize so much time had passed… And next time, knock before you come in."
"I did! A bunch of times! You were so focused you didn't hear me," Johan said, tilting his head as he eyed the pile of books.
"Since when were you into reading? And so many books?"
"I'll be resting in my room for a while, so I figured I'd make good use of the time," I replied casually.
"If you're bored, you could've played with me!"
"You're busy with lessons and training. Don't worry about me," I said, brushing him off.
Still, Johan looked unconvinced. "You're acting strange. Even your way of talking is different. You used to say 'I' as boku, not ore. And I've never seen you so engrossed in books before…"
He circled me, prodding my side as though checking for an impostor. His suspicion was fair—I'd changed in more ways than one. Explaining the return of memories from a previous life was out of the question, so I sighed, unsure how to handle him.
Then, Johan raised a finger, a mischievous glint in his eyes.
"Prove you're really my brother. What's my favorite food?"
"The bagel sandwiches from the town bakery," I answered immediately.
"What game did we play the most?"
"Hide and seek, followed by treasure hunts."
"Last time we played a board game, who won?"
"You did. I've won three times out of 655 matches."
"What's the pet I want most right now?"
"A fluffy cat."
"What's the biggest secret you're hiding from Father?"
"That you accidentally flushed the ring he bought you down the toilet."
"...Okay, you're definitely my brother," Johan said, crossing his arms and nodding.
Of course I am, I thought. Even with my past life memories, my time with Johan hadn't vanished.
Still, he furrowed his brow. "You're you, but you're not. It's like… you've turned into an old man or something."
"An old man?!" I blurted. "No, it's just—maybe it's the head injury. I'm sure I'll feel like myself again soon."
"Whatever," he said with a shrug, sitting in the chair next to me. "So, what are you reading? Whoa, you've written notes everywhere!"
"Magic history," I explained. "I've uncovered some fascinating details. Take a look at this—"
I gestured to my notes, but Johan's gaze remained on me, not the paper.
"Brother, I like you just the way you are. Even if you can't use magic."
His quiet words caught me off guard. For a moment, I hesitated, then reached out to ruffle his hair.
"Don't worry about me," I said, smiling. "I'm not doing this because of any inferiority complex. I just want to learn more about magic. That's all."
Johan pursed his lips but said nothing, his expression a mix of concern and curiosity.
He's a kind and clever child.
Despite growing up under immense expectations, he'd never once looked down on me. That alone had kept me from falling apart.
"Okay, enough of that," Johan said, swatting my hand away, embarrassed. "What now? Play a board game?"
"Hmm…" I trailed off, an idea sparking in my mind.
Research requires experiments. And if I can't use magic myself…
"Johan," I said, turning to him. "Will you help me with my studies?"
"Absolutely not!" he replied, recoiling in horror.
"Come on, you're so good at everything," I teased. "It won't take much effort."
"No way! I had hours of training today! Why should I do more work now?"
"Not work," I clarified. "I just need you to show me some magic."
"...Show you magic?" he asked, tilting his head in confusion.
I picked up a book from the table.
"This world's books explain how to use magic, but they don't delve into why it works. No one questions its origins or mechanisms—they just take it for granted. But if I understand the underlying principles, I might figure out why I can't use magic… or maybe even how to change that."
"You're not making any sense," Johan said, looking at me like I'd lost my mind.
But I couldn't help the grin spreading across my face.
This world's mysteries were ripe for exploration. The thrill of discovery coursed through me like a fire.
"I'll uncover the formula for magic," I said, clenching my fist in excitement.
Johan muttered under his breath, "He really did hit his head too hard…"