Slippery snow is turning to slush. It is midwinter in Kanto, time for bundling up in fleecy sweaters and heavy coats. But at the two Hikari Yochien schools in Kawasaki, boys and girls are playing outdoors wearing nothing more than gym shorts.

"We don't force children to take off their clothes," says school founder Naohiro Yoshida. "Kids would catch a cold if they were forced. They watch the elder kids, and when they feel ready, they take off their shirts by themselves."

Pupils at Hikari Yochien take part in painting (above) and taiko drumming classes (below).

Hikari Yochien's "naked education," an extension of the traditional practice at Japanese kindergartens of having children wear short pants in winter, has been widely written about and reported on television, both in Japan and abroad.