Going to work sick is okay if you don’t have a fever?

I work as an english teacher at a daycare/english school so i’m constantly exposed to germs. Unfortunately, my immune system still isn’t used to it so i’m more often sick than not.

Every time it seems I ask to go or stay home, they ask if i have a fever and if i don’t then im okay to work. I’ve had 38.0+ degrees celsius fever at work multiple times and they just tell me to drink some medicine and act like that’ll fix me.

Is this normal? I hear people say this is just how japan is, but cmon. Surely it doesn’t take someone with half. brain to realize that staying home while sick is better than going to work with 20-30 other kids.