Proof that the guarantor exists and lives in Japan.
What it must show
A 住民票 is issued at the guarantor's city hall for about ¥300, same day
Documents issued IN JAPAN are valid for only 3 MONTHS — do not collect them too early
Photograph BOTH SIDES of a residence card, all four corners, no glare
No translation needed
Notes
Do not collect the guarantor's 住民票 at the same time as yours if the packet is still weeks away — it expires in 3 months and you would be troubling them twice.