is a Japanese professional wrestler, better known by the ring name Io Shirai who is currently signed to the WWE, performing on their developmental brand NXT, where she is a former NXT Women's Champion. Making her debut in March 2007, Io spent several years working as a tag team wrestler, teaming with her older sister Mio, with whom she would wrestle for various promotions across Japan and Mexico, winning the TLW World Young Women's Tag Team Championship in the process. In June 2010, the Shirais came together with Kana to form the Triple Tails stable, which would last for fifteen months, before Io broke out of the group and started her singles career with the World Wonder Ring Stardom promotion. In April 2013, she won the promotion's top title, the World of Stardom Championship, which she would hold for over fifteen months. She is currently in her record sixth reign as one third of the Artist of Stardom Champions, while also being a former two-time World of Stardom Champion and a one-time Goddess of Stardom, Wonder of Stardom, High Speed and SWA World Champion. She is recognized as the "ace" of Stardom, and was named the 2015 and 2016 women's wrestler of the year by Tokyo Sports.