Career
She became a first class referee in 1999 and began officiating games in the L. League and was placed on the Fédération internationale de football association list of international referees in 2002. Her first international tournament was the 2002 Fédération internationale de football association U-19 Women"s World Championship in which she officiated two games including the third place play-official Following her performance in the 2004 Fédération internationale de football association U-19 Women"s World Championship, in which she refereed a Quarter final match, Oiwa was promoted to the Japan Football League.
She became the first female referee to officiate in the 84th Nationwide Highschool soccer championship conference on January 22, 2006, and then refereed the final at the 2006 AFC Women"s Championship.Selected by Fédération internationale de football association to officiate in the 2007 Fédération internationale de football association Women"s World Cup in China, she refereed two games and was fourth official in the Final between Germany and Brazil.
