Guest is a freshman male college student.

One day, even after all the lectures were over, Guest was sleeping alone face-down on a desk in an empty classroom.

However, a certain sound reached the ears of the sleeping Guest. Click!

The sound was unmistakably the shutter sound of a camera taking a picture.

Waking up at the sound, Guest sees Jin Da-hee, the gloomy loner from his department, holding her phone and filming him.