It was a quiet afternoon at Shirokuma High. The school courtyard was bathed in soft sunlight, and students enjoyed their tea break, chatting and laughing. Yet, for Hiragi, the calm was deceptive.
A sudden commotion erupted near the teachers' lounge. A teacher, Mr. Kuroda, collapsed mid-sip, clutching his throat and gasping. Panic spread instantly. Susi Sensei shouted for help while students froze in fear.
Hiragi rushed over, adjusting his hat as he scanned the scene. Mr. Kuroda's tea cup had been untouched moments before, and now it lay shattered on the floor. Hiragi knelt, carefully examining the remnants. A faint, bitter smell lingered.
"Poison," Hiragi muttered under his breath.
He quickly cordoned off the area and called in three potential suspects:
Mika, a student assistant who prepared tea for teachers. She looked genuinely shocked, but her hands trembled slightly. Hideo, a chemistry enthusiast who often experimented with harmless substances in the lab. He had been nearby moments before the incident. Aya, a quiet librarian who had access to the teachers' lounge through a back door.
Hiragi began questioning each one individually, carefully observing every reaction.
Mika stammered, "I… I always make tea carefully! I didn't—" Her eyes darted nervously toward the broken cup.
Hideo crossed his arms. "I was just walking by. I don't even like tea." But a faint speck of residue on his sleeve caught Hiragi's eye.
Aya's calm expression didn't falter. "I was in the library all afternoon. I didn't touch anything." Yet Hiragi noticed a slight smudge on her palm, barely visible.
Hiragi crouched near the cup remnants. Tiny crystalline traces sparkled faintly under the light—a chemical compound he recognized from his prior observations in the lab. The faint aroma matched a rare herbal poison used in controlled experiments.
He pieced the puzzle together. "The poison was slow-acting, tasteless, and almost impossible to detect without proper tools. Whoever did this counted on distraction and panic."
After a careful sweep of the lounge, Hiragi found the small vial hidden behind the sugar canister—its label missing. He smiled faintly. "A deliberate trail, but too subtle for most to notice. Clever, yet traceable."
Confronting the three suspects, Hiragi observed their reactions carefully. Mika's face turned pale. Hideo looked annoyed but avoided eye contact. Aya's calm demeanor wavered for a split second—the slightest twitch betrayed her.
Finally, Hiragi spoke: "The culprit hoped the tea would be blamed on accident. But the residue, the placement, and the timing all point to someone with intimate access to both the lounge and the ingredients."
Aya lowered her head, admitting quietly: "It was supposed to be a lesson… to scare him, not harm him."
Hiragi sighed, shaking his head. "Even lessons in shadows have consequences."
The teacher recovered after a mild antidote, and the school buzzed with whispers of the strange poisoning incident. Once again, Hiragi had unraveled a complex puzzle, reminding everyone that even the quietest corners of Shirokuma High hide dangerous secrets.