While most people associate marine sports with beaches, a stretch of the Yodo River running alongside the towering skyscrapers of Osaka's Umeda downtown area has become a magnet for local windsurfers.

Many of them were out on the river in early December 2014, braving temperatures below 10 degrees as chill winds swept across the water.

Keiichi Kitamoto, 55, who runs a windsurfing school and equipment shop right by the river, was among them. The Osaka native used to work as a sales representative for a chain of cake stores, but quit in 1989 to pursue his love of windsurfing, competing as a professional and eventually becoming a national champion.