Nagasato was born in Atsugi on July 15, 1987. In 2001, she was promoted to Nippon TV Beleza from the youth team. In the 2002 season, she debuted in Nadeshiko League. She became one of the division's top scorers in 2006 season. She also won the league championship 6 times (2001, 2002, 2005, 2006, 2007 and 2008). In 2010, Nagasato moved to Turbine Potsdam in Germany, where she won the Bundesliga's leading goal-scorer award. She also won the UEFA Champions League with that team. In 2013, she transferred to the English FA WSL club Chelsea. She joined Wolfsburg in early 2015 to play in a stronger league for the 2015 World Cup. In August 2015, Nagasato joined Frankfurt. On May 24, 2017 it was announced that she had signed with the Chicago Red Stars of the National Women's Soccer League (NWSL), she appeared in only 6 games in 2017 due to injury. In 2018 she was named Player of the Week for week 10. In October 2018, Nagasato signed with Brisbane Roar on loan for the 2018–19 season. On September 10, 2020, Nagasato made history by becoming the first woman to play for Hayabusa Eleven, a men's team in the Kanagawa Prefecture League; she joined on loan until prior to the beginning of the 2021 NWSL season. On October 26, 2020, newly-formed club Racing Louisville FC announced Nagasato as one of their first signings for the 2021 season.