This is the second of a five-part series on population woes caused by Japan's graying society and low birthrate.

At first glance, it's hard to tell what's wrong with Keiko Sawada.

"I don't hate being alone, but I do feel lonely at times," Sawada, a sociable and talkative woman, said during a recent visit to her one-room apartment in Nakano Ward, Tokyo. "Of course I'm worried about what will happen to me in the future. I'm 85, after all."