The morning street felt fresh, the cold air still lingering lightly among the neatly lined trees along the sidewalk. Raku walked slowly with his bag on his back, his steps calm yet rhythmic, as if following the steady beat of his heart. The sky was a pale blue, decorated with thin clouds drifting slowly in the wind.
On the left side of the road, small shops were beginning to slide open their doors, the sound of bells chiming as the first customers entered. The aroma of warm bread from the bakery slipped out, greeting the noses of anyone passing by. Raku glanced briefly, as if considering buying something, but then continued walking.
The sound of motor vehicles occasionally echoed, not too crowded since it was still morning. A few other students in different uniforms walked while chatting, their laughter light and carefree. Raku only glanced at them, then shifted his gaze forward.
Sparrows flew low, perching on power lines, chirping noisily as if welcoming the new day. The soft breeze brushed Raku's hair, making him push aside his bangs slightly so they wouldn't block his view.
Every corner of the street felt alive, yet calm. Morning flowers bloomed in the yards of houses, adding color among traditional wooden fences and simple concrete ones.
Raku kept walking past the intersection, pausing briefly when the light turned red, watching the neatly dressed workers rush toward the station. A contrast to himself, walking calmly, unhurried.
Sobu High School slowly came into view in the distance, a large building with white walls and glass windows gleaming under the sunlight. The street grew busier with students heading in the same direction. Some pedaled bicycles, others jogged lightly so as not to be late.
Raku took a deep breath, feeling the freshness of the morning mixed with the surrounding bustle, then stepped more firmly toward the school gate.
Raku entered the classroom with calm steps. The room was still quiet, only the morning sunlight streaming in through the windows, making the desks glisten softly. He placed his bag on his seat, pulled the chair, and sat down. His hand opened a textbook he had taken from his bag, the pages rustling softly at his touch.
The classroom remained silent, only the sound of birds outside could be heard. Raku read seriously, his eyes tracing line by line, occasionally frowning slightly when he encountered a difficult problem.
The classroom door slid open. Iroha entered with light steps, her face bright as if the morning bore her no burden at all. She saw Raku already sitting neatly while reading a book.
"Good morning," greeted Iroha in a cheerful tone.
Raku glanced briefly, closing the page of his book with his finger as a marker, then smiled faintly.
"Good morning, Iroha."
Iroha's gaze fell on the book Raku was reading. She tilted her head slightly, her eyes sparkling with curiosity.
"Wow, so diligent. Reading a book this early in the morning."
Raku closed the book slowly, then answered calmly.
"I still need to study more. Besides, if I study enough, I won't have to worry about school lessons."
Iroha smiled crookedly, her eyes half-narrowed, then spoke in a teasing tone.
"Your words sound exactly like a model student."
Raku was slightly surprised, looked at her briefly, then shook his head slowly.
"Maybe it's just a coincidence."
Iroha chuckled softly, covering her mouth with her hand while laughing.
"If you really make the top ten, I'll be shocked. And that clearly won't be a coincidence."
Before Raku could answer, the door slid open again. Shu, Ruri, Onodera, and Chitoge entered almost at the same time. The previously quiet classroom suddenly became more lively.
Shu raised his hand cheerfully.
"Good morning!"
Raku and Iroha turned simultaneously, then replied almost in unison.
"Good morning."
Ruri, walking behind Shu, immediately noticed Raku's desk. She saw the book still open, then smiled faintly.
"Studying early in the morning. Good. Don't be like him." She jerked her chin toward Shu, who had just placed his bag on his seat.
Shu was instantly shocked, opening his mouth wide.
"Eh, hey! I study too, you know!"
Shu's protest made Onodera cover her mouth, laughing softly, and Iroha also smiled in amusement.
Chitoge only sighed deeply, patting her forehead lightly while muttering.
"Noisy already this morning."
The classroom atmosphere slowly grew warmer, even though many desks were still empty, waiting for other students.
The classroom gradually filled with the sound of footsteps and light chatter. Students began arriving, some hurriedly putting down their bags, others immediately looking for friends to talk to. The atmosphere that had only contained Shu's small laughter and Ruri's light remarks now shifted into the typical bustle of a morning class.
Raku closed his book, exhaling softly. He observed the unfamiliar faces entering one by one, trying to remember their names, though not all were easy to memorize in just a day. Iroha sat at her desk, occasionally glancing at Raku, while Shu was already busy telling stories to two other boys who had just arrived.
Not long after—criiinggg!
The long bell rang, signaling the start of lessons. The noisy sounds gradually subsided, though there were still some whispers.
The classroom door opened. A woman with short brownish hair entered, carrying several sheets of paper and a marker. A friendly smile spread across her face, though her gaze remained firm.
"Good morning," said Kyoko-sensei, looking around the class.
"Good morning!" replied the students in unison. Their voices overlapped, some enthusiastic, some lazy.
Kyoko-sensei walked to the front of the blackboard, placed the papers on her desk, then picked up the marker.
"Today, Geography lesson. We will study about the structure of earth's plates, natural phenomena, and how they affect human life."
She began writing on the board:
"Plate Tectonics & Natural Phenomena."
Some students immediately opened their notebooks. The sound of pens scratching began to fill the class.
Kyoko-sensei explained while drawing a simple diagram on the board.
"As you know, the earth consists of several layers. On the outer part, there is the lithosphere, which is divided into large plates. These plates constantly move, although very slowly. And when these plates collide or shift, various natural phenomena are formed such as earthquakes, volcanoes, and even mountain ranges."
Some students looked serious taking notes, while others began to look absent-minded. Shu glanced briefly at Raku with a helpless expression, as if he was already overwhelmed from the start.
Kyoko-sensei continued.
"For example, the meeting of the Indo-Australian and Eurasian plates. In Indonesia, this collision produces many active volcanoes and frequent earthquakes. Now, who can give another example of natural phenomena caused by plate collisions besides earthquakes?"
The class fell silent for a moment. Some students glanced at each other, hesitant to answer.
Raku, who had been paying attention, slowly raised his hand.
"Volcanoes, sensei," he answered briefly.
Kyoko-sensei smiled.
"Exactly. Volcanoes are formed due to subduction, where one plate sinks beneath another, producing magma that then rises to the surface. Good, Ichijou."
The other students began to look more enthusiastic, partly because they felt challenged after Raku answered.
Sensei then wrote again on the blackboard, this time about the three types of plate boundaries:
Convergent – Plates colliding.
Divergent – Plates moving apart.
Transform – Plates sliding past each other.
"These three types produce different phenomena. For example, convergent can form mountains and ocean trenches, divergent can create new ocean floors, while transform produces faults like the San Andreas in America."
The classroom atmosphere became quite lively. Some students began to take notes faster, others nodded in understanding. Shu, though his face looked tired, still scribbled carelessly just to avoid being scolded. Onodera seemed focused, bowing while writing neatly, while Chitoge sighed softly but still paid attention. Ruri just sat silently, staring at the blackboard with her usual cold expression, but her hand moved quickly noting important points.
The sound of the marker against the board could still be heard. Kyoko-sensei drew the earth's structure with a simple diagram: inner core, outer core, mantle, up to the lithosphere.
"—And this movement of the plates is what makes the earth always alive, always moving. This world is not static. It works in its own way."
That sentence, for some reason, pierced into Raku's mind. His eyes blinked slowly… then his vision blurred.
Darkness.
When he opened his eyes, he was already standing again on a white beach. The sound of calm waves, the flawless blue sky. Yet, in front of him was a holographic light in the shape of a Chibi AI, floating in the air with a playful expression.
Beside it stood a black-haired man with a blurred silhouette. Raku felt he had seen him before, but his face was unclear.
The Chibi AI floated upward slightly, then clapped its tiny hands.
"Well then, let's continue the lesson you'll never hear from any teacher."
Its small voice echoed, yet sharp. It displayed a hologram of the globe, similar to planet earth, with tectonic plate lines splitting it.
"The earth—or any world—has a structure that determines its strength. Some worlds are strong, some are fragile. And this is what you must understand: not all worlds can withstand the burden of existence from beings like Outer God or Trihexa 666."
Raku swallowed hard, his eyes sharpening.
The black-haired man beside him frowned. "What do you mean… fragile worlds?"
The Chibi AI chuckled, its voice mocking.
"DxD, One Punch Man—those are strong worlds. Even a fully manifested Outer God can still be resisted without the dimension collapsing. But… Teyvat? Academy City? Fairy Tail? Small worlds like those would tear apart even before the battle truly begins."
The hologram of the planet changed: Teyvat with a glowing Irminsul, then the futuristic Academy City, and Tenroujima from Fairy Tail. All trembled, cracked, and shattered as a large dark silhouette—representing the Outer God—descended upon them.
"Just imagine, protagonists who dare to fight an Outer God in their own home. Hahaha…" The Chibi AI covered its mouth with its hand, its laughter sounding cruel yet mocking.
"Go ahead, destroy your own house, then sleep in the ruins of stars. The fastest game over scenario in history. Brilliant, isn't it?"
Raku froze, his breath caught. He could feel the mockery stabbing at him, as if directed right at him.
The man clenched his fist. "…So fighting an Outer God in one's own world is foolishness?"
The Chibi AI nodded quickly, with the face of a satisfied child.
"Of course. Do you think the Outer Gods don't know? They deliberately choose fragile worlds. They know not all realities have foundations as strong as DxD or OPM. And they wait for some fool to try becoming a hero in a glasshouse."
The hologram shifted again, this time showing a massive crack in a world, before collapsing into fragments of light.
Then, the Chibi AI's voice turned serious.
"That's why… battles against entities like Outer God or Trihexa 666 are only possible in isolated space. A place outside fragile multiverses. Isolated worlds, empty arenas, with no ties to the main reality. That battle isn't just about who is stronger, but how to save the world from being destroyed along with it."
Suddenly, the holographic light expanded, forming a cosmic map with thousands of stars. From its center, an image of an artificial planet appeared, gray-blue, lifeless.
The Chibi AI pointed at it.
"And this is where the Arc of Embodiment comes in. This Lost Magic, in the hands of an ordinary person, can only make silly swords or shields. But in the hands of someone who truly understands… you can weave together an isolated planet. An empty world, a place to discard, lock away, or fight beings beyond reason without tearing apart the multiverse."
Raku jolted. 'A planet?'
He looked down, staring at his own hands in that memory.
The black-haired man beside him also looked shocked. "…Creating a planet? That's… impossible."
The Chibi AI smiled slyly.
"Impossible? Only if you think small. Arc of Embodiment can't create living beings, true. But structures of empty worlds? Materials, fields, gravity, even atmosphere—that can all be created. The only limit… is your imagination and the energy you can channel."
Raku nearly lost his breath. 'An isolated planet… as the key to fighting the Outer Gods?'
But before he could think further, the image cracked like broken glass.
Crack!
Raku's consciousness returned. He gasped, his eyes opening. He was still sitting in Sobu's classroom, his notebook open in front of him. Kyoko-sensei capped her marker and turned toward the students.
"That's all for now. After the break, I'll give you practice questions about today's geography lesson."
Students began moving, standing from their seats, some leaving the class for lunch. The noisy sounds returned to fill the room.
But Raku just sat still. His heart was still pounding fast.
'Physics… Outer God… now Geography and Arc of Embodiment creating a planet?'