Over half the population of South Korea lives in high rise apartment buildings. Americans dream of white picket fences and Koreans dream of a condo overlooking heaven, err, bottleneck traffic insanity.
There are three rental systems in Korea: Jonsei (which means money in full) and 2 types of wolse system. About 68% of the rental market is under the Jonsei system. No monthly rent is paid; the tenant gives the landlord "key money" amounting to 25- 70% of the property value. At the end of the agreement, money is returned in full.
The wolse system involves monthly payments, but key deposits are required-- between 10-20x the monthly rent. The larger your deposit, the smaller the monthly payments.
Landlords profit through investments.