When Sasuke pushed the eraser across the line, Naruto nearly exploded.
The line had already been erased, leaving only cracks in the floorboards. But everyone had crossed it too many times these past few days, so they all roughly knew where it had been. The old eraser slid from Sasuke's hand, crossed that invisible boundary, and stopped in front of Naruto's shoe.
Naruto reached for it.
"Your feet," Iruka said.
Naruto's hand froze in midair. Sasuke lowered his head and kept writing, as though he had not been the one to push the eraser over. Kiyo stood by the door with his eyes wide and his mouth open, while Morita Yu had already reached over and covered his mouth.
Naruto pulled back his hand and glared at Sasuke.
"You did that on purpose."
Sasuke did not look up. "It slipped."
"Your hand slipped pretty accurately."
"You don't have to pick it up."
That was an easy thing to set someone off. Che heard it from nearby and even closed the wooden booklet in his hands halfway. Naruto's shoulders had already risen, as if he were about to charge over. But his toes stopped before the crack and did not move any farther. That invisible line blocked his feet—and held back the words he wanted to shout.
Iruka did not judge who was right. He only watched Naruto's feet.
"Steady yourself first."
Naruto gritted his teeth and planted his heels firmly. The corridor was so quiet that they could hear chalk softly rolling in the blackboard tray. Sasuke's pen stopped as well, only briefly, before continuing to write.
"Look."
Naruto lowered his head and looked at the eraser. The old eraser sat on the other side of the crack, half a step away. No one was going to step on it,