คาถาที่ยังไม่เสร็จหลังเลิกเรียน — 第一章 缺角的魔法阵

Chapter One: The Magic Circle Missing a Corner

The door of the empty classroom was unlocked.

Shirasaki Rin knelt on the floor, tracing a ring of intricate lines in white chalk. The pattern gave off a faint glow in the evening light, yet its easternmost edge was missing a corner, like a mooncake someone had taken a bite from.

“You’re in the wrong classroom.” She did not look up.

“I’m on duty.” Tōru held the mop in front of himself and felt as if he were confronting the supernatural with cleaning equipment. “That… is glowing.”

“Unfinished things glow.” Rin turned the chalk once between her fingers. “When they’re finished, they go out. Like a life.”

Tōru did not know which line he was supposed to answer. He only saw that her fingertips were white with powder, and that the corners of her eyes were red. The pattern gave a low hum and jumped. From the missing corner a small patch of color like sunset leaked out, then dimmed again.

“Don’t look.” Rin bent her body over the circle. “Look too long, and you’ll want to fill it in.”

“What happens if it’s filled in?”

Rin was silent for a long time before she said, “Then after school will end.”