Profile | Takashi Murakami, Japanese contemporary artist, on Japan after the Fukushima nuclear disaster, the meaning of the Superflat movement he launched, and his answer to Picasso's war painting Guernica

Consider the significance of weather in the history of contemporary Japanese art. On the morning of August 9, 1945, cloud obscured the town of Kokura. The crew of an approaching American B-29 Superfortress had planned to drop their payload, given the cartoon-ish nickname of Fat Man, on Kokura, but had emphatic instructions that the target must be visible to the naked eye. Unable to see clearly, they kept going and shortly afterwards completed their mission over a second town, named Nagasaki.

One of those fortunate children of Kokura went on, in 1962, to have a baby boy. She and her taxi-driver husband called their child Takashi Murakami.

"When I was a child, my mother would always talk about that moment, mostly in summer," he says, on a cloudy morning in Hong Kong. "She would say, 'Oh my God, that cloud looks like the one over Kokura.' This is timing! Timing!"

In Japan, they still use the term "Kokura's luck" to mean unwittingly escaping a terrible disaster, but it must surely leave a peculiar imprint if your childhood is spent being told your existence depended on the vagaries of climate.

Murakami grew up to become Japan's most successful commercial artist, and perhaps its most laid-back citizen (of which more later).

Even if you think you don't know his work; even if you get him muddled up with the other Murakami - that would be the writer, Haruki - you will probably have seen the multicoloured monograms or cherry-blossom designs he began creating for Louis Vuitton in 2003 and which have cheerfully enlivened the wardrobes of fans, and the coffers of knock-off merchants, ever since.

Failing that, you may have glimpsed the Google doodles he did to mark last year's summer and winter solstices. Once you start looking around, his creepily cute mushrooms, flowers and critters are everywhere.