It's not unusual for children to have an imaginary playmate. My neighbor in Denver had one that lived in the basement. It freaked me out at the time. Looking back, she was an only child in the middle of Denver, who wouldn't want an imaginary friend there?
Here in Tokyo, it's a little different. G has a Japanese mom. She sounds pretty awesome. Tonight she told G that she could run around in her birthday suit and not brush her teeth. We've been told that when she brushes G's hair, it doesn't hurt. She lives far away, but she comes around pretty often from what I can tell. She sounds pretty great and if she is anything like the Japanese moms around here, she looks great, too.