Talk:Shiina Mikado/@comment-79.55.151.213-20120110170017/@comment-99.100.21.132-20130521052515
I've heard that she might have Angelman Syndrome: it would explain why she's more often than not happy and smiling. It's also markedly noticable through signs of low mental developmental rates (easily mistakable for autism) as well as seizures, sleep disturbances, and jerky arm movements, such as arm-flapping.
Completely speculation though.