Kairi Hojo jumps at opponent Mieko Satomura during a female professional wrestling show in Tokyo on July 26, 2015.
The brutal reality of the ring is masked by a strong fantasy element that feeds its popularity with fans, most of them men.
Japanese rules on hierarchy also come into play, with a culture of deference to veteran fighters. Mieko Satomura carries her opponent Kairi Hojo through the audience area.
Kairi Hojo jumps at her opponent Mieko Satomura during their show.
American Kris Hernandez made her debut in August 2014 under the name Kris Wolf with a costume featuring a wolf's head and tail. "I fell in love with it - the drama, the excitement," the 31-year-old said of her first encounter with this unusual side of Japan.
American Kris Hernandez, shown here battling Starfire, became the first foreigner to train from scratch and work her way up into Japanese women's pro wrestling. She earns $250 for a weekly show - but that's not the point. "I was doing it because it was cool," said Hernandez, who is now on a break after suffering a concussion.
The rough and tumble may also be an outlet for many of the wrestlers in a country where women are usually expected to be demure and cute, Hernandez said.
"Sometimes it's a part of themselves that they cannot normally express," she said.
"I have met so many that are so sweet and shy outside the ring, and then you get into the ring and they explode."
Confetti rains on wrestler Act Yasukawa after her last match before retirement on Dec. 23, 2015.
Wrestler Kaori Housako jumps at her opponent Mieko Satomura.
A wrestler holds on to the rope during a show.
Yasukawa, right, jumps at Kairi Hojo during their show.