On May 20, 12-year-old Momo Shimizu is scheduled to fight 24-year-old Momoko Yamazaki in a mixed martial arts match in Tokyo. The fight on the Deep Jewels 16 undercard marks Momo’s amateur debut.

The fact that a pre-teen girl is fighting a grown woman is not sitting well with U.S. sports observers – just check out the comments on this report by WMMA Rankings.

In Japan, though, no one seems to be bothered.

“What’s the reaction (in Japan)? There’s almost nothing,” Shu Hirata, a manager and marketer with the Deep Jewels promotion told Bleacher Report.

“It’s been done before here, and fans are used to seeing kids doing kickboxing and beating adults,” Hirata continued. “If anything, there’s more of an expectation that she’s the next big thing. So her coach (Sadanori Yamaguchi) actually appreciates the concern from the U.S. side, because nobody is too concerned in Japan.”

To Hirata’s point, in 2011, 13-year-old Yukari Yamaguchi in her MMA debut beat 33-year-old Nana Ichikawa in 80 seconds. Last year, 12-year-old Karen Date submitted 28-year-old Ayumi Misaka.

Also, if this makes Americans feel any better, Momo’s fight will be contested under amateur rules: she and her opponent will wear protective head gear, shin guards and heavily-padded gloves; elbow strikes and strikes against an opponent on the ground are not allowed; and there will be only two three-minute rounds.

Said Hirata, who counts UFC straw-weight champion Joanna Jedrzejczyk among the fighters he has managed, “Of course there’s always a danger as you can never say it’s 100 percent safe. But if we’re talking about the danger of brain concussion, in that sense, I personally think kids’ football, soccer, even playground activities could cause more danger of getting hit to the head.”

That’s an important point to Americans who are up in arms about this. Their kids probably play Pop Warner.

Dr. Shawn Klein, a professor of sports ethics at Arizona State, said some of his concerns are assuaged if Momo is mature enough to understand what she’s getting into and she has the support of her family.

Momo checks both boxes.

“I would think on average, it would be wrong for a 12-year-old to do this, but I think there can be exceptions if you have a 12-year-old who is exceptional across the board,” Klein said, per Bleacher Report.

Momo has lots of experience in jiu-jitsu, kickboxing and karate, and while it’s too soon to be eyeing the UFC, she has aspirations to be a legit professional in MMA (her gym mate and Hakuhinkai Karate, 19-year-old Naoki Inoue, is 10-0 and recently signed with the UFC).

While Momo is modest ahead of next Saturday’s bout – “I don’t have firm confidence to win this fight. But I don’t think I would definitely lose or anything like that,” she said – Hirata is full of confidence.

“I think Momo is going to smash Yamazaki,” Hirata said. “…This might be one of the best prodigies coming out of Japan. Just wait.”

You can catch the fight on DeepFightGlobal.com.