Japan's ancient samurai swords were once used to slice apart enemies, but in a new fitness craze they serve to slash away at extra pounds and cut down on modern-day stress instead.
"Cut down!", a sword-wielding instructor shouted during a recent "Samurai Camp" gym session in Tokyo as a squad of sweat-drenched women warriors followed suit, slashing the air with their shiny blades.
"Put your right foot forward, cut down straight, thrust out your chest, no bending of the back," the instructor yelled to the sound of a techno dance beat and swooshing weapons. "Punish the extra fat with this!"
To avoid turning the health workout into a bloodbath, the swords are made of wood and urethane foam, but the determination of the participants is steely: the goal is to shed five kilograms (11 pounds) in about a month.
The popularity of the course, which comes amid a resurgence of interest in Japan's medieval warrior class, surprised even its inventor Takafuji Ukon, a 31-year-old choreographer, dancer and fitness expert.
Last year Ukon initially targeted men when he introduced the swords in an exercise class in his mirror-walled aerobics-style studio -- but instead found women enthusiastically flocking to the martial workout.
"I thought swords are for men and fans are for women. That was wrong," he told AFP in his studio, where more than 100 women have signed up for classes that cost 2,000 yen (about 20 dollars) per hour.
Ukon has no martial arts training but is a master of sword dancing, which is believed to date back centuries with roots in dances performed by samurai warriors to pacify the souls of the dead.
"I thought it would be great if I could bring exercise and Japanese traditional performing arts together to help people have fun and lose weight," said Ukon, whose mother is a teacher of traditional Japanese dancing.
"This allows women to be someone they thought they could never be. I think what made them become so absorbed in this is that they can look at themselves in the mirror and feel ecstatic about becoming someone with a sword."
During the recent session, chuckling students advised each other: "Say sorry if you hit other people" and "Don't retaliate".
Ukon told them: "You'll learn four basic patterns first -- the body slash, frontal cut-down, slant cut and reverse slant cut -- and then we will proceed to their combinations."
Samurai may have been famously stoic and hardened fighters, but Ukon's advice was more New Age -- he told his charges to visualise their enemy as body fat and as the negative emotions and impulses in their minds.
"We don't live in an era of slashing people," he said. "What we cut down is the negative things in ourselves."
One of the students, 20-year-old publishing employee Midori Ito, said afterward: "I sweated and twisted my waist a lot. Swords are fun."
Another enthusiastic student was Kazuko Ueda, a 40-year-old manager at an information technology company and confessed aerobics class drop-out.
"Holding a sword is very original. It's also fun to get in touch with Japanese culture a bit, and flinging a sword and cutting makes me feel good.
"I feel like I'm slashing evil people, as if I had become a samurai or a hero in a period drama."
Another student, a 33-year-old pharmaceutical lab assistant, said it was hard to keep up with the instructor "but it was fun to hack away".
If the exercise were a real battle with metal swords, she added, "I heard we would be slashing a thousand people or more in one lesson."