Here is some helpful vocabulary if you’re renting in Japan:
[thank you money / key money] Usually at least one month’s rent. It’s a gift to the landlord.
[deposit] In some cases, it’s three months worth! The deposit is not really a deposit since it’s only partially refundable, even if the rental is undamaged.
[guarantor] From what I’ve experienced and heard from my Japanese friends, the guarantor must be a Japanese national, over 40, with a stable career and reasonable salary.
Friend A’s father passed away. Despite his mother’s stable job, she could not become his guarantor. The friend paid an extra month’s deposit, and the agency waived the need of guarantor.
Friend B’s 22-year-old girlfriend, a dental hygienist, became his guarantor.
All of these factors are highly variable on the rental agency and the individual agent you’re dealing with. Some places don’t require all of the above mentioned. Negotiations are possible too, but don’t expect to do this in English or broken Japanese. Step up your professionalism and use keigo.
I have never experienced any xenophobia or discrimination with the apartment rental agencies in my four experiences moving.