London Olympian Daiki Kamikawa won his second over-100-kg title on Saturday on the first day of the national invitational weight-class championships.
Kamikawa produced a come-from-behind victory in the closing seconds of the final with a wazaari to defeat Ryu Shichinohe. It was Kamikawa's first title in three years.
"Kamikawa's mentality has changed, and the substance of his judo has changed along with it," Japan men's coach Kosei Inoue said.
The event serves as a qualifier for Japan's team to the world championships in August.
In the women's 48 kg, 18-year-old Ami Kondo defeated her corporate club teammate Emi Yamagishi.
The women's 57-kg division was thrown into disarray when London gold medalist Kaori Matsumoto lost in the first round as Nae Udaka claimed her third championship.
Yuka Nishida defeated Misato Nakamura to win the 52-kg title, the third of her career and her first in five years. At 63 kg, Yuka Osumi won her first title.
Yuya Yoshida and Yusuke Kumashiro won their first championship at the event in the men's 90 kg and 100 kg, respectively.
