The Japan Women's Open Tennis is a professional women's tennis tournament played on outdoor hard courts. The event is affiliated with the Women's Tennis Association (WTA), and is an WTA 250 tournament on the WTA Tour. As successor to the Japan Open the event was held in women-only form for the first time in 2009, and was the second tournament of the season held in Japan: the Pan Pacific Open, a Premier 5 tournament, was held two weeks before. In 2015, the event was moved from Osaka to Tokyo and in 2018 to Hiroshima, before returning to Osaka in 2023 after a three year hiatus. It's also currently sponsored by Kinoshita Group.