Asada, the 2008 and 2010 champion both of which came in Korea, has had to settle for silver for the past two years running first behind Miki Ando and then Ashley Wagner.
However she ensured it wasn't third time unlucky as she followed up her impressive short program, in which she reintroduced her trademark triple axel, with another fine performance in the free skate.
Akiko Suzuki and Kanako Murakami, both second and third respectively after the short program, maintained their positions for a Japanese clean sweep but neither were near Asada.
Asada, the favourite with rivals Kim Yuna and Wagner opting not to compete in Osaka, led Suzuki by almost ten points following the short program and went on to extend it to win by more than 15.
She was downgraded on her triple axel in the free skate but her other elements were solid as she finished on 205.45 points in total with Suzuki second with 190.8 and Murakami third with 181.03.
Meanwhile in the pairs Meagan Duhamel and Eric Radford ended a run of six straight Chinese victories to become the first Canadians since Jamie Sale and David Pelletier to win the title.
Duhamel and Radford won bronze in 2010 and silver in 2011 but led Canadian teammates Kirsten Moore-Towers and Dylan Moscovitch after the short program after scoring 70.44 points.
Moore-Towers and Moscovitch turned the tide in the free skate scoring 130.45 to Duhamel and Radford's 128.74 but it wasn't enough to overthrow them and take the gold.
Duhamel and Radford won by just over a point while American's Marissa Castelli and Simon Shnapir took home bronze with an overall combined total of 170.10.