With her dazzling win, Nakai clinched a spot in the JGP Final, and Kataise, making his long-awaited circuit debut, impressed with his jump landings.
Men’s runner-up Rio Nakata and women’s bronze medalist Ami Nakai were emotional when their free skate scores were shown during their JGP debuts.
The nation’s skaters will be participating in the Junior Grand Prix this season after missing it the past two years.
The 18-year-old, who placed second at the Beijing Olympics, is the favorite to win the world title this week.
Daisuke Takahashi and Mao Asada were the first two skaters to sweep both singles titles for Japan, doing so at the 2010 world championships.