10 Candidates For WWE's Upcoming Women's Tournament

As she's the ace of Japanese women's promotion Stardom, there's arguably no female wrestler outside of WWE with the credentials of Io Shirai. The currently reigning World of Stardom Champion has held every championship in the promotion - meaning that, at 26 years of age, she's accomplished just about all she can in the company.

Shirai made her debut at age 16, teaming with older sister Mio Shirai for a variety of Japanese women's independent promotions, but also making appearances for All Japan Pro Wrestling and Pro Wrestling Zero1. As time wore on, the sisters competed for other leagues like Smash and Oz Academy, forming an alliance known as Triple Tails with current NXT Women's Champion Asuka.

In 2011, Shirai joined Stardom and began her domination of the promotion. She's since gone on to hold all of Stardom's titles, claim victory in the 2014 5STAR Grand Prix, and become the inaugural SWA World Champion (a belt borne out of an alliance between Stardom and other international promotions). All that's left for Shirai is to make a splash in the U.S., and she can do just that in the Women's Classic.