The 65-year-old is known as the mother of the sport in Japan, with a tough, exacting coaching style.
From 1978 to 2004, her swimmers brought home 4 silver and 7 bronze Olympic medals.
Synchronized swimming at the Olympics consists of duet and team events. Imura -- a former champion herself -- demands that her swimmers have speed, height out of the water, and perfect synchronization.
"Swimmers say 'this is all I've got.' But I don't believe that. I know they can do more. I know they can improve. So I use every tactic I've got to make them better," Imura says.
In 2007, she shocked Japan by moving to China to coach the Chinese national team.
Some questioned her decision, given the edgy relations between the 2 countries.
"The political situation didn't bother me. I wanted to show the world that Japan's synchronized swimming is beyond exquisite, to trademark Japan's style. The Beijing Olympics was the perfect stage and I didn't want to miss the opportunity," Imura says.
Under her guidance, China's team went back to basics. Swimmers cried as they did endless sit-ups and extensions.
But it worked. After a year, Imura led the team to its first-ever Olympic medal in synchronized swimming. China overtook Japan, and currently stands at number one in Asia.
China's success prompted criticism of Imura back home. Japan had slumped after she left. The squad failed to make the podium in the team event at the Beijing Olympics. In London, they left with no medals.
But in 2014, Imura returned to Japan as a coach of the national team.
Her first move was to work on her swimmers' mental game. Compared to China, she felt Japan's team lacked the determination to win. So she made the women compete against each other. To polish their technique, she made them train over 10 hours a day.
The effort paid off. Japan won its first medal in 8 years at last year's World Championships.
Now, for Olympic glory, Imura is challenging her swimmers to compete at an even higher level. They've added a radical lift to their routine, where the jumper has to twist her body as she leaps.
"Coach says we have to be extra hard on ourselves now. We believe her. We're doing it," says Yukiko Inui, a member of Japan's Synchronized Swimming Team.
Synchronized swimming events at the Rio Games start on Aug. 14. Twenty-four teams will compete in the duet, and 8 teams in the team event.
"I want my team to win a medal and experience the true privilege of being top athletes," Imura says. "I hope they'll feel it was worth sticking with my tough training and not giving up. I hope these young women will reach accomplishments beyond their dreams through the Olympics. That's my ultimate goal."