Taking a Sick Leave is ok but REMEMBER …
Koreans do not take frequent sick leaves due to illness. But exceptions are there for foreign teachers. The employment contract includes generally 3 sick leaves in a year.
Teachers are required to notify the employer and submit an accompanying proof of illness from a doctor.
If you are taking sick leave, then, do remember that you might be visited by your employer and he or she would take you to hospital. So, you cannot take sick leave for short vacations.
Since your co-workers are automatically the often-unwilling recipients of your classes if you call in sick, it’s not a good idea to do so unless you really are sick. Hangovers, or just having a bad day, won’t be acceptable excuses for missing teaching to either coworkers or management.
Legally, for any sick day taken, your employer can deduct a day’s salary unless you present an official note from a doctor. In practice, most employers don’t ask for this note unless someone has been absent for more than one day or has a history of one-day illnesses.