TOKYO (Reuters) - Male office workers at a telecoms firm in Tokyo have experienced simulated menstrual pain to help them become more sympathetic toward female colleagues ahead of International Women's Day on Friday.

EXEO Group workers winced at a company event on Thursday as a "perionoid" device sent electric signals via pads placed below the navel to stimulate the lower stomach muscle and induce a cramping sensation.

"I couldn't move. It hurt to the point where I couldn't stand," said 26-year-old Masaya Shibasaki after using the device jointly developed by researchers at Nara Women's University and startup Osaka Heat Cool.

"I now understand women have to work while fighting this pain every month. It's actually amazing how women can do that. I really respect them," Shibasaki said.

EXEO said it wants to create an environment where its more than 90% male workforce can be more supportive of female peers, including when it comes to taking menstrual leave.

Companies in Japan are legally required to allow women to take menstrual leave. However, there is no requirement for the time off to be paid and surveys showed around half of female workers never take it.

"We hope those who experienced (menstrual pain) today go back to their workplace and speak about how they felt, and spread their understanding," said EXEO public relations officer Maki Ogura.