A Year On from Fukushima: Japan's Unquiet People

Dominic Nahr / Magnum for TIME

Mother Courage Chieko Natori organized radiation tests in her Tokyo suburb

Chieko Natori doesn't look like an activist. On a January day in Tokyo, her tiny frame is lost in the boho-chic layers of a Japanese yuppie. She carries no banner or petition — just rice crackers that she hopes will entice her son to walk with her. He ignores her, sinking to the sidewalk and refusing to move.

Though Natori, 38, may not be having any luck shifting her toddler, since Japan's 2011 nuclear disaster she has mobilized thousands of citizens. "I never did anything like this before," says the onetime food-and-gardening blogger. But last March,...