Naohide Yamaguchi on Nov. 7, 2020. (Kyodo)

Japan's Naohide Yamaguchi rewrote his own record in the men's 100-meter breaststroke for swimmers with intellectual disabilities on Saturday, clocking 1 minute, 4.13 seconds during a domestic event.

Yamaguchi shed 0.82 second on the SB14 class record he swam to win the world championships in September last year in London, which essentially booked a spot for him in the Tokyo Paralympics.

In the women's 50-meter backstroke, 14-year-old Miyuki Yamada logged 1:11.25 to set a Japanese record in the S2 class for swimmers with limited use of their arms and hands, at the meet in Rifu, Miyagi Prefecture.