The number of single-person households is mushrooming here, and so are instances where people are found dead in their own homes days after their death, which has already become a social concern in Japan.

Around 200 to 300 households may live in close proximities in Korea's tall apartment buildings, but the traditional concept of a neighborhood has been disappearing for some time.

One office worker who has lived in an "officetel" -- an apartment for either office or living space -- in Sinchon, Seoul for three years, says the only person in the building he has spoken with is the janitor. He only knows what his next-door neighbor looks like. "There is really no need to get to know your neighbor when you live in an officetel, and I don't want them to find out about who I am either," he said. "Unless my neighbor opens the door and screams, there is probably no way of knowing whether they’re in trouble."

According to Statistics Korea, there were 4.03 million single-person homes in Korea as of 2010, accounting for 23 percent of the total 17.33 million households. In 1980, single households accounted for only 4.8 percent, rising to 9 percent in 1990 and 15 percent in 2000. The ratio of single-person homes has grown five-fold over the last 30 years and doubled over the past two decades.

The growth exceeds government projections. Statistics Korea said in late 2009 that single households would account for 23 percent of all households after 2030, but actual developments have beaten the forecast by 20 years.

Kim Yong-hak, a sociologist at Yonsei University, said, "We are seeing a rapid weakening of social networks among the disadvantaged, with poor people becoming increasingly alienated, while the rich expand their personal connections."