A 4-1 victory over Cerezo Osaka on Saturday gave Sanfrecce an unassailable four-point advantage ahead of Vegalta Sendai, and with it their maiden J.League title.
The Japanese champions will now represent the host nation at December’s tournament, beginning with a tie against Oceania representatives Auckland City on December 6 in Yokohama.
Al-Ahly, Chelsea, Corinthians, Monterrey and Ulsan Hyundai have also qualified for the competition, which concludes on December 16.
Yojiro Takahagi, Toshihiro Aoyama and Hisato Sato scored first-half goals to send Hiroshima on its way to the one-sided win. Hironori Ishikawa added another after the break to widen the lead.
Title challengers Sendai, a team that brought inspiration to a region still coping with the aftermath of last year’s devastating earthquake and tsunami, needed a win against relegation-threatened Albirex Niigata to keep their hopes alive, but were beaten 1-0 at home before a capacity crowd at Yurtec Stadium.