Japanese high school student Shiho Sakai has set a new world record in the women's 100-metre backstroke, winning in 56.15 seconds at the Japan Open short course swimming championships in Feb 2009. Sakai, one of Japan's top hopes for the London Olympics in 2012, broke the previous mark of 56.51 set by Natalie Coughlin of the United States. "Of course, I set out to set a new world record. I'm very surprised that I did and I'm very, very happy about it," said a jubilant Sakai. "From now on, I'm going to aim for the national championships in April 2009 and qualify for the world championships."