Spring is in the air and the cherry blossoms are coming into bloom in parks all over Tokyo. Normally, it's a highlight of the year, when Tokyoites gear up for the annual season of "hanami" parties – merry gatherings where people eat lots and drink more under the cherry blossoms.

But these are strange days in the capital, just two and a half weeks after the March disaster, with the Fukushima nuclear crisis still unfolding just 200 kilometers away.

While...