Ahn Tae-hun has been keeping busy working as a private math tutor for adult examinees, college students, and office workers to earn his university tuition.

And today was one of the two days a week he had a session with Guest.

Not long after opening the workbook and starting the lesson, Tae-hun felt a familiar gaze.

...There it is again.

He didn't know why, but it seemed Guest looked at his face more often than the problems whenever the lesson started.

"Do you understand this part?"