They moved down the corridor slowly, Ozu pointing out each classroom one by one.
"That's Miss Takahashi. She teaches math," he said, voice low as if simply naming teachers might somehow get him in trouble.
Hayato peered inside as they passed. The teacher stood at the board, chalk moving briskly, students scribbling notes. No aura. No shadow. Just an ordinary woman doing an ordinary job. He glanced at Nabi, and she shook her head slightly. Nothing.
"Next is Miss Ayame. She handles English."
Inside, the teacher read aloud with perfect pronunciation, students repeating after her. Again, Nabi's eyes narrowed, her wings hidden but her senses sharp. She glanced at Hayato once more. He shook his head. Still nothing.
"Miss Honda. Literature."
The teacher's voice floated through the hall, poetic, students hanging onto every word. There was warmth in her tone, the kind of voice that calmed a room. Hayato tilted his head. "Yeah, not exactly demonic."
"Agreed," Nabi murmured.
They continued: history, arts, music, gym, etc. Each time, Ozu muttered the name and subject, and each time, both angels found nothing. No shift in the air. No shadow of despair. Just normal. Almost boringly normal.
By the time they reached the end of the hall, Ozu stopped and blinked. "That's… uh… that's everyone, I think."
Hayato exhaled through his nose. "So we're just chasing shadows now? Great."
Nabi, however, frowned. Her instincts told her something was missing.
Then Ozu froze. He slapped his forehead with his palm, the sound echoing down the hall. "How could I forget?!"
Hayato and Nabi both turned sharply.
Ozu adjusted his glasses nervously. "There's… one more. Miss Kasiba. She teaches science."
He hesitated, lowering his voice. "…But she's not always here first thing in the morning. Sometimes she comes in late."
Hayato's eyes narrowed. Nabi's gaze sharpened, icy-blue irises glowing faintly.
Neither said a word, but the same thought coiled in their minds. Red flag.
They exchanged a glance and followed Ozu onward.
The three of them stopped just outside the science classroom. From within, a woman's voice carried, smooth and measured.
"Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost."
At first, it sounded like any other lecture—a teacher explaining a principle with clarity, her tone calm and professional.
"This," she continued, "is the principle of equivalent exchange. It is balance. A law as absolute as gravity, as constant as time."
Hayato tilted his head, listening. Huh. Doesn't sound too bad.
Inside, students sat quietly at their desks, pens scratching, hanging onto every word.
"Think of it this way," the voice went on, a faint lilt creeping into it now. "If you desire strength, something must weaken. If you want knowledge, something must be forgotten. To create, something must be destroyed."
Her words flowed smoother now, like silk draped over glass.
Ozu whispered quickly, "She always does this at the start of class. We… can't go in until she's finished. Trust me."
Nabi's eyes narrowed, lips pressed into a firm line. She said nothing, but her posture grew sharper, as though every word in the air was a blade.
The teacher's tone dropped lower, velvet-soft yet heavy. "Remember, children: no gift comes free. No miracle is without cost. The universe demands payment in full. Those who try to take without giving…"
There was a pause. The silence stretched long enough that even outside, Hayato felt his skin prickle.
"…are thieves."
Her voice sharpened just slightly on that last word, slicing through the air. The students inside didn't flinch, but Hayato felt it lodge in his chest like a hook.
He exhaled slowly, his hand brushing against his side where his shotgun usually hung. Okay… yeah. That's not just science talk anymore. That's… creepy.
He glanced at Nabi. She didn't look back, but the cold shimmer dancing faintly at her fingertips told him everything.
They both sensed it. Evil.
Miss Kasiba's voice grew softer, almost coaxing now, wrapping around the students like silk.
"To gain what you desire… you must be willing to give something in return. Think of your own lives—your time, your comfort, your effort. All things must be sacrificed if you want results."
Her tone turned sharper, but no less smooth. "Science itself proves this. Energy cannot be created or destroyed. It only changes form. You must sacrifice something to transform it into something else. To achieve. To succeed."
She let the words hang for a moment, then her heels clicked against the tile floor. "For today's lesson… a simple demonstration. Gather your beakers and burners. Take water. Boil it. Watch as it changes, as the liquid becomes steam, only through the sacrifice of heat."
Her sultry voice lowered even further. "Remember: nothing comes without a cost. Not even the simplest things."
"Now," she said suddenly, her tone snapping back to professional briskness, "partner up and get to work."
"Yes, Miss!" The class echoed in unison, chairs scraping as the students began moving.
From outside the door, Hayato leaned back, muttering under his breath, "She's the one."
Nabi's eyes flickered like shards of ice. "I agree."
Beside them, Ozu shifted uneasily, glasses sliding down his nose. "But… she's so kind to everyone. All the students love her."
Hayato turned to him, his face suddenly serious. "Ozu. Thanks for helping us but I need you to go back to class. Right now. Just in case."
Ozu's eyes widened. He hesitated but then nodded quickly, clutching his bag and hurrying down the hall.
Hayato watched him leave, then exhaled slowly. His knuckles brushed against the doorframe. No more waiting.
He raised his hand, and knocked.