Sae Miyakawa on Sunday captured her fourth straight vault title and won the floor for the first time at the apparatus national championships, a qualifier for the world championships in the fall.
Asuka Teramoto defended her beam title as she and Miyakawa secured their spots at the worlds in Montreal in October, joining already qualified Mai Murakami and Aiko Sugihara on the team.
In the men's competition, Yusuke Tanaka won his first parallel bars title, while Kazuyuki Takeda claimed his second straight rings crown as eight world championships candidates were decided.
A maximum of four gymnasts will be selected for the remaining spots in September following a training camp.
Kohei Uchimura, who secured his ninth straight individual all-around title at the NHK Cup last month, has already qualified for the worlds along with Kenzo Shirai.
Olympic and world all-around champion Uchimura won the high bar for the second time in a row and Shirai took his fifth straight floor title. Shirai could only manage seventh on the vault after taking a fall.
