Glossary
Rentai-hoshounin (joint personal guarantor)
A human co-signer with joint-and-several liability for your lease — the landlord can demand the full amount from them first.
A rentai-hoshounin is a person who signs your lease and accepts joint-and-several liability, meaning the landlord can come to them for unpaid rent or damage costs in full, immediately, without trying to collect from you first. This is heavier than the Western idea of a co-signer. The role traditionally fell to a Japanese parent or employer, which is exactly why foreigners struggle — few have anyone willing to take on that exposure. The guarantee company replaced it for most deals, but premium landlords now sometimes ask for both, and a personal guarantor who actually qualifies is hard to find on short notice.