While Japan fights centuries of traditional gender norms to raise the status of women in the workplace, a small group of women are challenging convention in the ring.

Kairi Hojo jumps on her opponent Mieko Satomura as they fight in the stands during a 2015 Stardom female professional wrestling show in Tokyo, Japan. | (REUTERS/Thomas Peter)

Japan's all-female pro wrestlers are called "joshi puroresu," and their style, like their male counterparts', is less gimmicky than American pro-wrestling. Though matches still involve performance art, they can also be quite violent, with full-contact moves causing more injuries and shorter careers. But the sport isn't a new phenomenon.

Wrestler Io Shirai executes a moonsault onto Mayu Iwatani. | (REUTERS/Thomas Peter)

Professional wrestling began in Japan after World War II, in an attempt to raise the country's deflated spirit. Women joined the sport soon after, in the 1950s, but really got their footing after the inception of the Japan Women's Pro-Wrestling Association in 1967. In the 1970s, while the major men's wrestling associations began splintering, all-female wrestling reached a new height of popularity. During the next two decades, some female wrestlers became breakout stars and pop icons, their muscular looks and athletic skills helping to challenge Japan's strict gender norms.

Today, joshi isn't nearly as popular as it was in its heyday, but a smaller, dedicated contingent carries the torch. Sure, audiences for female wrestling matches remain largely male, and the athletes' wild, flashy costumes and outsized personalities play into the sport's entertainment value, but the ring is still a sacred place for these female athletes. Stepping into it, they shed society's conventions. "I have met so many [wrestlers] that are so sweet and shy outside the ring," one wrestler told Reuters photographer Thomas Peter, "and then you get into the ring and they explode."

Below, a look at Japan's female wrestlers in all their glory:

Kaori Housako jumps on her opponent Mieko Satomura. | (REUTERS/Thomas Peter)

Mieko Satomura carries her opponent Kairi Hojo through the audience. | (REUTERS/Thomas Peter)

Wrestlers scatter across the ring. | (REUTERS/Thomas Peter)

Wrestlers Kris Wolf and Starfire fight. | (REUTERS/Thomas Peter)

Wrestlers fight. | (REUTERS/Thomas Peter)

Act Yasukawa jumps at Kairi Hojo. | (REUTERS/Thomas Peter)

Wrestler Kris Wolf receives ice spray treatment. | (REUTERS/Thomas Peter)

Ticker tape confetti rains on wrestler Act Yasukawa after her last match before retirement in December. | (REUTERS/Thomas Peter)