"Radiation! Bang bang!"

Gesturing as if with guns, two boys in Tokyo repeatedly taunted a girl whose family fled to the capital to escape radioactivity unleashed by the Fukushima nuclear crisis in 2011.

Tormented by headaches and weight loss, the girl began to skip classes, and switched schools to escape the bullies, her mother said. But the very radiation that uprooted the family brought more pain in her new home.