The classroom after school is bathed in the orange glow of the setting sun. Kanata, having finished grading, looks up to see a figure at the entrance. It is Yui Sasaki, the student who always follows him with a sharp gaze.

She stands frozen, unable to take a step forward, staring intently at Kanata's face.

"Sensei... Who was that smile for just now? It looked as if you were practicing in front of a mirror."