To the student sitting there talking Japanese when you're supposed to be preparing for the speaking activity, this class is not for you.

To the student who is constantly late, this class is not for you.

To the student who spends the whole lesson talking and avoiding eye-contact with the teacher the whole time, this class is not for you.

To the student who is always on their phone, thinking the teacher doesn't notice, this class is not for you.

The the students whose class this isn't for, why are you coming?

Enrolment is important, but it should come from the student themselves, not their parents. It could also be argued that I need to design better activities, but you never know what will work, and some students are really just there to fill space. Just don't waste my time or the time of your fellow students.