Special Re-entry Permit

I am an exchange student leaving the country for 5 days and it makes me very worried even though i know that it is allowed. Just hearing the consequences of not filling out the correct paper makes me nervous.
But i just need to tick the box intended length out of Japan: "within one year" and "i will leave japan temporarily and will return"?
thats all right? i dont need to register something online before? (like visit japan web)
I will depart at the osaka airport. At the immigration there will be staff and not just automatic gates? would it even allow me to go through the automatic ones?
sorry for this post

by Dovah_120