The classroom air turned heavy the moment the announcement echoed through the intercom. Final tests.
Reina leaned back in her seat, eyes narrowing, not because she was worried—she could ace them as always—but because of the two gazes burning holes through her from across the room. Slowly, reluctantly, she turned her head.
Hana and Kaito.
Both wearing the exact same expression she dreaded—wide, pleading, desperate hope. Reina's inner voice instantly repeated in a flat tone: no. no. no. no. no.
And yet, just as she expected, the second the homeroom teacher left the classroom, they made a beeline for her desk.
"Reina, please!" Hana begged, practically throwing herself against Reina's table."Teach us again!" Kaito added, attempting to sound cool but failing under the weight of his own panic.
Reina let out a long, heavy sigh. Her fingers tapped against her notebook. Why must it always be me…
Then Ayumi walked over more calmly, hands clasped together as she smiled reassuringly. "Don't worry, Reina. We'll make it worth your time. We just… really need you again."
Before Reina could formulate her sharp refusal, a knock came at the classroom door.
Every head turned.
Shion.
He stepped inside with that easy smile of his, and when his eyes found Reina, they brightened further. He strode across the room like he belonged there, stopping right at her desk. Reina blinked up at him, confusion tightening her brow.
"...Why Shion is here?" she asked bluntly.
He chuckled. "Because I need help too. Math has never been my friend. I've always put everything into music, but… if I want a shot at a music university, I'll need better grades."
Reina stared. Flat. Expressionless. "..."
That was all the cue Hana and Kaito needed. They instantly grabbed onto him, tugging him closer like he was a secret weapon.
"See?! Even Shion needs you!" Hana exclaimed."Come on, Reina, one more time! Please!" Kaito added, desperate but still trying to look unfazed.
Reina pinched the bridge of her nose, sighing deeply. "...This afternoon. At my lab."
Hana squealed in victory. Kaito huffed, pretending to recover his pride. Shion only chuckled, clearly amused by the whole display.
The afternoon sun filtered through the tall windows of Reina's laboratory, scattering faint lines of light across the polished floor. The room had been cleared and reorganized earlier by ANIER under Reina's command; shelves and tools pushed neatly against the walls, wires tucked away, devices folded into their compartments. At the very center of the space sat a low square table, wide enough for several students to gather around. Cushions had been placed in a careful circle, though Reina did not bother to sit cross-legged; she folded neatly instead, with her back perfectly straight.
Shiro, her white cat, was sprawled lazily on the corner of a shelf, tail flicking from time to time as she watched the humans gather.
Hana and Kaito flopped onto the floor like two children about to start a board game, excitement written across their faces. Ayumi adjusted her skirt and sat down properly, calm and composed. Shion, carrying nothing but a notebook and a pencil, settled beside Reina. He gave her a small smile as if to thank her, but Reina avoided his gaze, expression unreadable. And lastly, Himari had quietly slipped into the circle, placing her textbooks gently on the side before bowing her head slightly in thanks.
Above them, Reina's halo floated upward on command, then anchored itself to the center of the ceiling. Its crystalline ring hummed faintly as ANIER's projection expanded into a soft, glowing hologram. The air shimmered, and a neatly written study schedule appeared suspended in light above the table:
Mathematics
Science
English
Japanese Literature
Japanese History
"Today we start with mathematics," Reina said. Her tone was clipped and efficient, though not harsh. "We follow this schedule precisely. Distractions will not be tolerated."
"Eh? No snacks?" Hana groaned, leaning against Kaito.
"No snacks," Reina replied flatly, already pulling up the first set of problems.
The Math Lesson
The hologram shifted, letters and numbers forming out of thin air until the problem was displayed in front of everyone. The glowing text hovered, as if written on an invisible board:
Problem: Prove that the sum of the first n odd numbers is equal to n2n^{2}n2.
Reina folded her hands on her lap. "This is easy. I expect all of you to understand it."
Ayumi raised her hand immediately. "That's simple, isn't it? We can—"
"Don't," Reina cut her off, raising one slender finger. "Ayumi, Shion, Himari—you are forbidden from answering this one. Hana, Kaito. This is for you."
Hana blinked. "Us?!"
"Yes. Show me what your minds are capable of."
Kaito cracked his knuckles, trying to look confident. "Leave it to me. This is just… soup, right?"
"Soup again?" Hana echoed, nodding furiously. "Knowledge is soup!"
Reina pressed her fingers to her temple, sighing audibly. "If you mention soup one more time in my laboratory, I will revoke your study privileges."
Both of them sat upright instantly, hands on their laps, as if disciplined children.
They bent forward, whispering furiously to each other, scribbling numbers into their notebooks. It took them much longer than it should have—ten minutes of crossed-out calculations, confused muttering, and Hana accidentally drawing a cat instead of a number. Reina said nothing, her eyes half-lidded, her patience visibly thinning.
Finally, they slammed their work onto the table.
"The sum of the first n odd numbers," Hana announced proudly, "is… is… n squared!"
Kaito pointed at their paper, smudged with pencil lines. "See? We did it. Perfect logic."
Reina leaned over, skimmed their explanation, and pinched the bridge of her nose. Their proof was clumsy, the steps disorganized, and the reasoning nearly incomprehensible. But—despite everything—it was correct.
"…You are promoted," Reina muttered.
Hana's eyes sparkled. "Promoted?!"
"Yes. From idiot… to smarter idiot."
Both Hana and Kaito cheered as if they had been knighted. Ayumi covered her mouth with her hand to hide her laughter. Shion chuckled openly.
Reina sighed again. "This is exhausting."
Advanced Problems
Without pause, she waved her hand, and the hologram shifted to display more complicated problems. The easy warm-ups vanished, replaced by dense equations and word problems written in elegant light.
"Now, advanced mathematics. You may all participate."
Ayumi immediately straightened, Himari leaned forward, and even Hana and Kaito stopped grinning and began to concentrate. Shion twirled his pencil between his fingers, a faint smirk still on his lips.
As expected, Ayumi and Himari handled the advanced set smoothly, their notes clean and methodical. Hana and Kaito struggled but managed—slowly but steadily—to reach the correct answers, their faces tense with focus.
When Reina moved into expert-level mathematics, the atmosphere changed. The problems stretched into realms most high school students had never touched—proofs of limits, abstract algebra, obscure theorems.
Ayumi furrowed her brow, biting the end of her pen. Himari's notebook filled with half-finished equations, but she kept trying, her soft voice whispering suggestions to Ayumi.
Meanwhile, Shion tapped his pencil against the page, completely lost. His background was music, not mathematics, and though his grades were decent, Reina could see him struggling against the weight of the abstract logic.
She reached out without hesitation, drawing his notebook closer.
"Watch carefully," she said, her voice softer than usual. She began writing step by step, her neat handwriting cutting through the confusion. "You're skipping transitions. Don't jump. Follow this path—like a melody, but exact."
Shion tilted his head, watching her hand move. "Like a melody… I see."
Her explanation was gentle, patient. The sharpness she often used with Hana and Kaito was gone, replaced with calm precision. Even Ayumi noticed, glancing up briefly before returning to her own work.
By the time they reached the ridiculous math—a set of problems Reina herself had devised—only Reina could solve them without hesitation. Her halo pulsed faintly as ANIER assisted in presenting the steps in holographic clarity. The others watched with varying degrees of awe and despair.
When the last problem dissolved into particles of light, Hana collapsed backward onto the cushion. "I'm dead. Bury me in numbers."
"You're not dead," Reina replied dryly, already erasing the board. "Just incompetent."
Kaito raised a shaky hand. "Still… I got further than last time. So… maybe I'm—"
"—a smarter idiot," Reina finished for him.
Hana and Kaito exchanged a proud high-five anyway.
Shion leaned back with a relieved sigh, Ayumi smiled faintly in triumph, and Himari adjusted her glasses, still scribbling notes to revise later.
Reina exhaled quietly, her expression unreadable. For her, it was just another study session. But watching them work, argue, and laugh in her lab, the once-silent space felt… warmer than usual.
The numbers faded away from the glowing board, replaced by a new shimmering set of diagrams, questions, and charts. ANIER's calm voice filled the room, tone measured and faintly mechanical.
"Proceeding to science. Problems have been tailored to each participant's current level."
Hana and Kaito immediately leaned toward each other, their notebooks clattering against the table.
"Let's do this together again!" Hana grinned.
"Of course. With my brains and your…" Kaito hesitated. "…enthusiasm… we can't lose."
"You mean with my brains too," Hana pouted.
Reina pressed two fingers to her forehead and exhaled sharply. "Just solve it without commentary."
Across the table, Ayumi and Himari were already working side by side, exchanging short, precise remarks in low voices. Himari's handwriting was tidy, every formula lined up, while Ayumi underlined keywords and circled important terms.
Shion had his pencil poised over the page but hadn't started writing yet. Reina's eyes lingered on him before she finally leaned a little closer. Her voice softened.
"Is there anything you don't understand?"
Shion shook his head, eyes glinting as he glanced at the diagrams. "Not really. Science feels like music to me—patterns, resonance, rhythm. It clicks easily."
Reina studied him silently for a moment. She didn't correct him, though the comparison was unorthodox. Instead, she pointed at one of his half-written answers. "Tighten this step. Otherwise it's correct."
He adjusted his writing at once, smiling faintly as if her approval mattered more than the answer itself.
While Shion wrote, Reina remained beside him, her hair brushing his shoulder as she leaned over. She gave the occasional hint, a direction here, a reminder there. Unlike Hana and Kaito, she didn't need to scold—Shion followed her guidance with an almost musical flow, and that alone calmed her.
After nearly an hour, the problems were finished.
Reina gathered their papers one by one, scanning with her sharp, critical gaze. Her verdict was short but firm.
"Prepared enough. All of you."
Hana and Kaito grinned proudly, though they were clearly only barely above Reina's threshold of satisfaction. Himari and Ayumi nodded in relief. Shion leaned back, content.
The English Struggle
The hologram flickered again, now displaying a fresh set of essay prompts and grammar exercises.
"English," Reina announced.
Almost immediately, Ayumi, Himari, and Shion began writing smoothly, their sentences clean and fluid. Ayumi's style was formal, Himari's was simple and clear, and Shion's had an odd poetic rhythm to it—like song lyrics.
Meanwhile, Hana and Kaito froze.
"What does this word mean?" Hana whispered.
Kaito squinted at his paper. "Why is there a silent letter? That's cheating."
Their answers quickly devolved into chaos—sentences that made no sense, grammar bent beyond recognition. Hana proudly wrote, 'The apple is red because red is apple,' while Kaito's essay included, 'I am smart but grammar is dumb.'
Reina's pen scratched violently across their pages. She didn't even sigh this time—her face was simply blank, resigned.
"…No. Just no."
She turned toward the ceiling. "ANIER. Take over."
"Understood," ANIER's calm voice replied, its holographic projection shifting into an interactive grammar board.
As ANIER began breaking down rules and walking Hana and Kaito step by step, Reina leaned back, exhaustion softening her posture. For the first time that afternoon, her shoulders slumped slightly.
Shion noticed immediately. Without saying a word, he shifted just enough for her to rest against him. Reina stiffened for half a second, then exhaled and allowed herself to lean her back on him.
"…Thank you," she whispered quietly, the words barely audible.
Shion only smiled, his eyes focused on the lesson continuing in front of them.
By the time ANIER was finished drilling them, Hana and Kaito had managed to produce essays with proper grammar—barely acceptable, but leagues better than their earlier disasters.
Reina flipped through them with a sharp gaze. "Pass."
Hana jumped in triumph. "Yes!"
Kaito raised his fist. "We're geniuses."
"Barely literate," Reina corrected.
Still, they looked proud.
The Weight of History
The last subject appeared on the hologram: Japanese History.
A collective groan echoed across the room, except from Ayumi, who looked calm and ready. Hana slumped forward onto the table dramatically. "Not history! Anything but history…"
"History is easy," Reina said flatly, lifting Shiro into her lap. "It is reading, memorizing, and writing. Nothing more."
Shiro purred, settling comfortably as Reina's hand absently stroked her fur.
This time, Reina delegated entirely. "ANIER, handle the lesson."
"Understood."
The AI projected timelines, dates, and key events across the air in neat holographic charts. The students took notes as best they could, scribbling frantically while ANIER summarized each period with calm precision.
Ayumi wrote diligently, every detail in order. Himari followed closely, though her notes were more compact. Hana and Kaito, however, struggled to stay awake. Their pens slowed, their eyes glazed.
Reina continued petting Shiro, her gaze sliding briefly toward Shion. He was still writing, though slower, his movements growing heavy. His head dipped once, then again, as if fighting against invisible weight.
"...You'll collapse like that," Reina said quietly, her tone softer than the words.
Shion shook himself awake, rubbing his eyes. "I'm fine. Just—history always makes me sleepy."
"Obvious," Reina murmured.
Break Time
After several hours of study, ANIER dimmed the hologram. "Session complete. Recommend a rest period."
Reina gave a short nod. "Break."
The group sighed in relief almost in unison, dropping their pens and leaning back. Hana sprawled dramatically across the floor, Kaito stretched his arms with a groan, Ayumi massaged her wrist, and Himari rubbed her eyes.
Reina rose quietly, moving toward the small counter at the edge of the lab. She set water to boil with precise movements, preparing tea leaves in a pot. The warm scent soon filled the room.
She poured each cup with practiced grace, placing them on the table one by one. When she reached Shion, she lingered for a second longer before sliding his cup forward.
"For your drowsiness," she said softly.
Shion smiled knowingly. "I thought so." He lifted the cup carefully, the rising steam warming his face. "Thanks, Reina."
Her reply was only a small nod, but her expression eased ever so slightly, just enough for him to notice.
The hologram flickered one last time, the faint letters unfolding in crisp lines of calligraphy-like script.
"Final subject: Japanese Literature."
This time, Reina didn't need to explain. She folded her arms and leaned back slightly, Shiro curled against her lap as though sensing the shift in mood.
"No more teaching," she said plainly. "Just testing. ANIER has already prepared the papers."
The AI confirmed with a soft chime, and fresh sheets printed out in a neat stack before each student. Pencils scratched across the room. For a while, only silence remained, broken only by the occasional tap or sigh.
Reina watched them quietly, her gaze calm but intent. Shion's brow furrowed in focus, his handwriting fluid, almost artistic. Ayumi moved swiftly, confident and steady. Himari was slower, careful in her word choice. Hana and Kaito, of course, struggled, whispering occasionally before Reina's sharp cough silenced them.
By the time the last paper was placed in her hand, Reina had already started grading. Her eyes scanned line after line, her red pen moving with precision. For a long moment, no one dared to speak.
Finally, she placed the stack down with a faint sound.
"All of you pass," she announced.
The room erupted with sighs of relief and faint cheers.
"Colorful pass," she added, tapping her pen against Hana and Kaito's papers. "Some barely, some brightly. But a pass is a pass."
"Yesss!" Hana threw her hands into the air.
Kaito stretched his arms, pretending nonchalance. "As expected."
Reina gave them both a flat look. "Don't get cocky. The real final still waits. And it won't forgive foolish mistakes. If you fail—don't think of dragging me into the blame."
Hana shrank slightly, but still smiled. Kaito just chuckled nervously.
The Quiet After
With the session complete, the group began to gather their belongings. Pens, papers, and textbooks were tucked away, chairs slid back, bags hoisted over shoulders.
Hana bounced toward the door, still brimming with energy. "Reina, we'll do our best in the final! See you then!"
Kaito followed, trying to look dignified but stumbling slightly under the weight of his bag. Ayumi lingered a moment longer, bowing politely. "Thank you, Reina. This helped more than you think."
Reina only nodded, her expression as unreadable as always. "Don't waste it."
Then they were gone, the door closing softly behind them.
The lab fell into a calmer silence. Only Reina, Himari, Shion—and Shiro, now curled into a ball on a warm pillow—remained.
Reina exhaled, a faint, tired smile tugging at her lips. "Finally… quiet."
Himari tilted her head. "Then let us help. After all, your lab is… messy after all this rearranging."
"It wasn't messy," Reina muttered, though her eyes softened. "…But fine."
Together, the three began moving things back into place. Reina directed with short gestures, pointing where each shelf, table, or device should return. Himari followed dutifully, carrying stacks of books, while Shion handled cables, monitors, and tools without complaint.
The hum of equipment slowly returned to its usual arrangement. Reina's workspace regained its symmetry—precise, minimalist, hers again.
When the final piece was set down, Reina gave a quiet sigh of satisfaction. "…Better."
Shion brushed his hands off. "Feels more like your space again."
"Exactly," Reina said softly. She glanced between Himari and Shion, her eyes warmer than usual. "...Thank you. Both of you."
Shiro purred in agreement, as though sealing the moment.