Uta Abe won her first World Judo Championships gold medal on Friday, while her brother Hifumi defended his men's under-66 kg title.
Abe beat compatriot and defending champion Ai Shishime in the women's under-52 kg final. Abe won all five of her matches at the National Gymnastics Arena by ippon.
"I haven't been this happy all year," Uta Abe said. "It wasn't different from any other international meet."
At 18 years and 2 months, she became the second-youngest Japanese woman to win a world championship title, following two-time Olympic champ Ryoko Tamura, who won the under-48 kg class in 1993 when she was 18.
In the men's under-66 kg final, Hifumi Abe defeated Kazakhstan's Yerlan Serikzhanov, after winning his semifinal match against Rio de Janeiro Olympic silver medalist An Baul of South Korea in extra time.
"My style is to go for ippon victories, but I was able to compete in a way suitable to the circumstances, and that allowed me to win," Hifumi Abe said. "I think it's a sign that I'm maturing.
"My target, more than winning consecutive titles, was for us to win as brother and sister. Once my younger sister won, I went into my final even more resolved to win."
It is the first time Japanese siblings won gold on the same day at the worlds.
