Risako Kawai defeated defending women’s 57-kg champion Rong Ningning of China on Thursday to capture the third world championship gold medal of her career.
Kawai had booked her spot at next year's Tokyo Olympics in the 57-kg division the day before by winning her semifinal. The 2016 Olympic 63-kg champion, Kawai secured Japan's third gold medal at this world championships in Kazakhstan's capital.
"I showed some of my failings as well as some of my strengths in the final," Kawai said. "I have areas where I'm solid, and then suddenly I'm faced with things that need work.
"I want to get even stronger, so I intend to put the one year I have before the Tokyo Olympics to good use," she said.
In the women's 76-kg class, Hiroe Minagawa fell in the final to Adeline Maria Gray of the United States, and will leave the worlds with a silver medal. Like Kawai, Minagawa was already guaranteed a spot on next year's Olympic team by virtue of having advanced to the final.
Kawai's younger sister Yukako failed in her bid to follow in her sibling's footsteps with a championship when she lost her 62-kg third-round match. Japan's Olympic 68-kg champion, Sara Dosho, also lost in the third round, as did men's 65-kg freestyle defending champion Takuto Otoguro.
Any of the three could still qualify for the Tokyo Olympics if they make it through the repechage to earn a bronze medal.