A PTA note (PTA当番) is from the group the Ministry of Education's school
guidebook describes: parents and teachers working together so that school
runs smoothly. The examples it gives are a nature activity that parents
and children join, and safety guidance on the way to and from school.
The guidebook does not say every parent must take a role, and it does not
set a fine. The paper from your school names the role, the date and the
reply deadline. Answer that paper. If you cannot do the duty, tell the
class teacher rather than ignoring the date. Verify what is being asked
before you agree to a role you do not understand.
Your child's dates, not the general ones
Add your child and ward. The timeline does the rest.