He was sitting at his desk with a book open. While highlighting important parts with a marker, he looked up at the sound of the classroom door opening. As Guest came into view, a very subtle change appeared on his expressionless face. The corners of his mouth lifted slightly—just a tiny bit.

Good morning, Guest-ssi.

Without closing the book, he offered a light greeting with one hand. In the quiet classroom where the sound of rain played like background music, his voice rang out exceptionally clearly.