LAS VEGAS – Their Olympic medals – a bronze in judo in 2008 for Ronda Rousey, a silver in wrestling in 2004 for Sara McMann – are what have brought them together.
But the two stars of UFC 170 are vastly different people with tremendously different goals, dreams and approaches to their sport.
They'll fight for the women's bantamweight championship Saturday at the Mandalay Bay Events Center in the first match of Olympic medalists in UFC history.
They are bonded by their desire to leave the arena Saturday with the belt in tow.
Though their differences in style, demeanor and outlook are blatantly obvious, Rousey and McMann share much more than meets the eye.
They are the best 135-pound fighters in the world, but on the surface, that's where they seem to part.
Rousey is the biggest name in women's mixed martial arts and perhaps in all of the sport. She's a darling of the media and a budding movie star. She's brash, colorful and entertaining and is never at a loss for words. She's seized the opportunity to become a star and, like superstar boxer Floyd Mayweather Jr., she carefully thinks of ways to promote herself.
Some have suggested Saturday's pay-per-view results will suffer because of the loss to injury of former light heavyweight champion Rashad Evans in the co-main event. He's been replaced by unknown Patrick Cummins, who will make his UFC debut against Daniel Cormier.
Though all four fighters in the main and co-main event are undefeated as professionals for the first time in UFC history, the foursome has just five combined UFC bouts between them (Rousey 2, McMann 1, Cormier 2, Cummins 0).
And Rousey just fought in December and admits she worries if the quick turnaround will impact her pay-per-view sales.
"I get concerned," Rousey said. "I do have my concerns about this pay-per-view. It's a really quick turnaround so I really haven't given people a chance to miss me. And this is after two huge cards, the Super Bowl card and the New Year's card. When I'm the headliner, all of the pressure really does fall on me to deliver. … I do worry about these things."
In that vein, McMann couldn't be more opposite of her opponent. McMann is an unusually quiet, fiercely private woman who insists she's not fighting for fame, money or glory.
The champion is generally considered the face of the division and, in some cases, of the sport. That's not a burden that McMann is eager to accept.
When it was suggested to her that she'd have to do more media and make more public appearances if she were the champion in order to promote her bouts, McMann seemed uncomfortable.
"Well, unless I fought an opponent who liked to generate attention and then they could do that," she said. "Yeah, I'd have to do more media stuff, but I don't think I'd change who I was to sell a pay-per-view."
Doing interviews before a major fight gets to be monotonous. The same questions are asked repeatedly and it quickly can get old. For those fighting Rousey, it's often about avoiding her famous arm bar, as well as competing in the vast shadow she casts.
McMann answered those questions repeatedly, though she didn't offer up much when talking about how she'll avoid becoming victim No. 9 of Rousey's arm bar.
"You'll have to watch the fight to see," she said, grinning.
What they share in common is unspeakable tragedy.
Much like Rousey before her UFC 157 match with Liz Carmouche last year, McMann was put in the highly uncomfortable position of discussing some of the most personally intimate details of her life.
Last year, Rousey angrily and tearfully demanded that the media quit asking about the suicide of her father, Ron, saying she'd never speak publicly about his death again.
McMann, too, has felt the searing pain of an untimely death of a loved one, not once but twice.
Her older brother, Jason, was murdered at Lock Haven State University in 1999. And in 2004, McMann's fiancée, Steven Blackford, died in an automobile accident.
Athletes often share insights from their lives in order to promote themselves and help advance their careers. But dealing with the deaths of those closest to you is extraordinarily hard, and it's easy to understand why neither woman would want to talk about such things.
Talking publicly about the loss of a loved one can be cathartic to some, but it just as easily can seem exploitive.
Neither Rousey nor McMann ever brings the tragedies up without being asked about it first. Rousey has already made it more than clear she won't discuss it again.
Jessica Eye, who fights Alexis Davis on Saturday's undercard, is dealing with a significant tragedy of her own. Eye's father is dealing with advanced cancer, and Eye speaks openly of his issues in part to try to help alleviate some of her own pain but mostly to attempt to raise money to help him get needed treatment.
That's not the path that either Rousey or McMann wants to take, and it's their decision and it deserves to be respected.
They've reached the pinnacle of their professional lives in dramatically different ways. Personally, they're as different as two could be: one a mother, one single; one starring in movies, the other shunning the limelight.
But they share a bond they'll never speak about and one only they can understand.
The story now, and going forward, should be whether McMann's wrestling can solve Rousey's judo, or whether Rousey continues her assault on history.
Their back stories are part of what made them the women they are today, but it does not define them nor should it constantly follow them. They've moved on from their tragedies to make themselves the best in their chosen profession, and that should be more than enough.