Nineteen-year-old Aaron Wolf won the men's 100-kg division on Sunday, the final day of the Kodokan Cup at Chiba Port Arena.
Born to an American father and Japanese mother, the Japanese-speaking Wolf won the title for the first time after earning a comeback ippon victory over Shohei Shimowada with an uchimata inner thigh throw in the final.
"I had confidence I could get back into the match, he was tired too," said Wolf, who was behind by two yuko points before coming up with the title-winner, 41 seconds from time. "I believe winning matches in front of me will eventually lead to the Olympics."
London Olympic representative Daiki Kamikawa claimed his first title in two years in the over-100-kg rank, where youngster Yusei Ogawa, 19, finished third.
Kota Otsuji won his first 90-kg title after Masashi Nishiyama, the bronze winner at the London Games, was knocked out in the second round.
Among the women, 2010 world champion Yuka Nishida, who missed both the Beijing and London Olympics, won her second consecutive 52-kg title.
"I was hell bent on winning. I wonder why it is that I simply cannot give up (on the Olympics)," said the 29-year-old. "There are many wrestlers fighting above the age of 30 (overseas) and they are my motivation."
Megumi Ishikawa clinched her first 57-kg crown in four years, while Aimi Nouchi and Fuuna Tonaki were crowned champions for the first time in the 63-kg and 48-kg classes, respectively.