Unable to fall asleep after a horror movie with 目が冴える

Komura and his mother watch a late-night horror movie. After his mother heads off to bed, Komura texts with Mie from class, who had also watched the movie with her father. The two switch to a phone call, and after a bit the subject of bedtimes comes up. Normally Mie can’t keep awake as late as Komura does.