In April 2004, Nagasato was selected the Japan national team for Football at the 2004 Summer Olympics – Women's tournament qualification. At this competition, on April 22, she debuted against Thailand. She was also part of Japan's 2008 Summer Olympic team and 2007 World Cup. Nagasato was part of the Japan squad that won the 2011 World Cup. She played as a substitute in the final against the United States. The game went to penalties and Nagasato had her penalty saved by Hope Solo, but Japan still emerged victorious.