When I renewed my visa I naively assumed that it included an extension of the re-entry permit.
I didn’t find out that this is not the case until I was at Narita airport going through passport control.
Passport control officer: “So, you’re not coming back to Japan?”
Me: “Of course I’m coming back, I’m only going on vacation.”
Passport control officer: “So where’s your re-entry permit? This is expired.”
Me: “Here it is look, I renewed it in April.” *points to the new visa*
Passport control officer: “This is your visa. You also need a new re-entry permit!”
Luckily they issued one at the airport, but only for a single entry. I have to go back to the immigration centre to get a new multiple re-entry permit.