Some Japanese Landlords Charge “Key Money”
Talking about Japan, there's another odd practice that is one of those forced voluntary things you occasionally come across in life, with the premise that you don't have to do it but, you know, you sort of do. It's something known as reikin, or key money, in this instance.
Key money is an advance payment you make to the landlord when you have the opportunity to rent an apartment in Japan. This payment is regarded as a gift. Saying "thank you for letting me rent this flat" would be analogous. However, since you won't receive the flat if you don't make the payment, it's also not strictly a gift. And you never receive a refund. Additionally, neither a deposit nor rent will be paid with it. Literally, it's just money spent for nothing.
Rent for a few months or even six months can serve as the key funding. All were paid in advance, and as this is a gift, there are no refunds whatsoever. What makes you think you'd ever pay it? Because someone else will if you don't.
The good news in this situation is that not all landlords demand it. However, those who anticipate it are unlikely to be persuaded otherwise. Additionally, if you want to haggle with a landlord who does have requirements, you might just talk yourself out of renting the house.