How Asia's MMA unicorn One Championship is taking on the UFC

Mei Yamaguchi is five-foot-nothing and built like a bulldog, barely standing taller than the top rope in the gym in suburban Tokyo where she trains. Yamaguchi, a 36-year-old wrestler, boxer and martial artist, has been fighting for more than a decade, but for most of her career competed in small venues in front of crowds of family and friends, working part-time jobs so she could devote herself to training.