Otani was born in Koka on May 5, 1979. After graduating from Keimei Gakuin High School, she joined Tasaki Perule FC in 1998. She became top scorer for 3 years in a row (2001-2003). In 2003 season, she was also selected MVP awards and the club won Nadeshiko League championship. In 2005 season, she became top scorer again. However, the club was disbanded in 2008 due to financial strain. So, she retired end of 2008 season. She scored 150 goals in 180 matches in Nadeshiko League. She was also selected Best Eleven for 6 years in a row (2001-2006).