Two-time world champion Haruna Asami scored an ippon against Dayaris Mestre Alvarez of Cuba in the women's 48-kg final on Friday, successfully defending her crown to lead a gold-medal sweep for the host nation on the opening day at the Tokyo Grand Slam.
In a resurgence of form in international competition, Japan won all five weight categories contested and dominated with three all-Japanese finals at Yoyogi National Gymnasium.
Yuki Hashimoto captured the women's 52-kg title in a victory over Nodoka Tanimoto, and 18-year-old Anzu Yamamoto beat Nozomi Hirai in the 57-kg final to claim her first title.