Uta is also a student of her sport, using the example of her brother, three years her senior, to mold her talent.

She holds Hifumi in awe, insisting "my brother is a role model not just to me but to all judoka."

In a sport dominated by Japanese athletes, the Abes are perhaps the most exciting of them all given that neither has come close to fully realizing their potential.

There is a modesty in both, which, on occasion, is overtaken by confidence in their own abilities. For Hifumi, it is not simply a case of whether he will win Olympic gold in front of his home crowd.

"I will win the 2020 Olympic Games," he declared of his 66kg class in which he is already the world champion.

Fear factor

Growing up in Hyogo, some 300 kilometers away from Tokyo, their father, Koji, worked as a firefighter. Hifumi took up judo at the age of six.

But Hifumi's start in the sport proved an inauspicious one.

"When I started judo at the age of six, at first I was scared -- but I learned to like it very quickly," he said.

His rise has been meteoric, wowing crowds with his dynamic, fast-paced style. His average winning time is currently just two-and-a-half minutes.

Hifumi's eagerness to learn is also present in his sister, who has been on a judo mat for almost as long as she can remember. For her, all of the toil is worth it for that moment of victory.

"Judo is hard," she said. "However, it's all worth it when you throw your opponent and win. Also, I think it's unique in the way it brings people together."

Last December, they achieved the unique feat of both winning their respective divisions at the prestigious Tokyo Grand Slam.

"Winning the Tokyo Grand Slam with my sister is a great memory," explained Hifumi. "We both share the same goals, and we will continue to support each other."

Rio regret

As shining lights for one of the Japan's favorite sports ahead of a home Olympics, both with feel the pressure build from an expectant public.

"I was very surprised when I won my first Grand Prix title [in Dusseldorf last year]," says Uta.

"This win gave me a lot of confidence. And now Tokyo 2020 is two years away and it's coming up fast. Having the Olympics in your country is a great honor.

"I feel the spotlight is on me more and more. This motivates me to do more, and perform even better."

For Hifumi, it's a chance to prove himself on the greatest stage of all after missing out on qualification for the Rio 2016 Games, something that still eats away at him.

He said: "I was very upset in not making the 2016 Olympic Games. I wonder how I would have done if I had the chance to fight there."

Both have aspirations to win gold in Tokyo, few would bet against them.