South Korean writer Eun Seo-ran was happily single, until a medical emergency made her want family around to help. But she took an unconventional route: legally adopting her best friend.

The 44-year-old lives far from her biological family, who are not actively involved in her life. She's not married and, like many people in low-birthrate South Korea, she has no children of her own.

But Eun does have a very good friend: Lee Eo-rie. The pair, who are not romantically involved, own property together, live together, share bills and have taken care of each other during illness.