- Born: 05/08/1990 in Kamakura, Kanagawa, Japan
- Birthname: Masami Odate
- Height & Weight: 5'1.5", 119 Ib
- WWE Women’s Tag Team Championship (2 times) – with Dakota Kai
- NXT Women’s Championship
- NXT Women’s Tag Team Championship – with Zoey Stark
- Artist of Stardom Championship (6 times) – with Mayu Iwatani and Takumi Iroha (1), Kairi Hojo and Mayu Iwatani (1), HZK and Momo Watanabe (1), AZM and HZK (2), and HZK and Viper
- Goddess of Stardom Championship – with Mayu Iwatani
- High Speed Championship
- SWA World Championship
- Wonder of Stardom Championship (2 times)
- World of Stardom Championship (2 times)
- Joshi Puroresu Grand Prize (2015, 2016, 2017)
She is best known for her time in World Wonder Ring Stardom, where she was a former two-time Wonder of Stardom Champion and a six-time Artist of Stardom Champion, while also being a former two-time World of Stardom Champion and a one-time Goddess of Stardom, High Speed and SWA World Champion. She was recognized as the “ace” of Stardom, and was the recipient of the 2015, 2016 and 2017 Tokyo Sports Joshi Puroresu Grand Prizes.
Making her debut in March 2007, she 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, she and her sister came together with Kana to form the Triple Tails stable, which would last for fifteen months, before Io broke out of the group and embarked on her singles career in Stardom.
Io quickly became one of the promotion’s top stars, and in April 2013, she won the promotion’s top title, the World of Stardom Championship, which she would hold for over fifteen months. Io worked for Stardom from the promotions inception in 2011 until June 2018, when she resigned from the promotion and signed with WWE.
In 2019, after losing out to Shayna Baszler for the NXT Women’s Championship, Io turned heel and sported a new, darker image. After almost two years working in NXT, Shirai finally won the Women’s Championship in a triple threat match against title holder Charlotte Flair and other challenger Rhea Ripley in the main event of NXT TakeOver: In Your House.
At SummerSlam 2022, she made her main roster debut as part of a new stable with Bayley & Dakota Kai. WWE gave her a new ring name of Iyo Sky. She later won the tag team titles with Dakota Kai on an episode of Raw in September.
Other Notable Achievements
TLW World Young Women’s Tag Team Championship – with Mio Shirai
Captain’s Fall Six Person Tag Team Tournament (2009) – with Gami and Mio Shirai
TLW World Young Women’s Tag Team Tournament (2009) – with Mio Shirai
5★Star GP (2014)
Artist of Stardom Championship Tournament (2017) – with AZM and HZK
Goddess of Stardom Championship Tournament (2015) – with Mayu Iwatani
Goddesses of Stardom Tag Tournament (2015) – with Mayu Iwatani
Red Belt Challenger Tournament (2013)
SWA World Championship Tournament (2016)
5★Star GP Best Match Award (2015) vs. Mayu Iwatani on August 23
5★Star GP Technique Award (2013, 2017)
Best Match Award (2015) vs. Meiko Satomura on December 23
Best Match Award (2016) vs. Mayu Iwatani on December 22
Best Match Award (2018) with Mayu Iwatani vs. Kagetsu and Hazuki
Best Tag Team Award (2015) with Mayu Iwatani
MVP Award (2013, 2014, 2016)
Outstanding Performance Award (2017)
Americas World Mixed Tag Team Championship – with Nosawa