Osada participated in her first international competition as an alternate for another skater, Megumi Aotani, at 1980 Enia Challenge Cup in the Netherlands at the age of 15.

Although her poor standings in compulsories caused her to place 6th overall, she received the special Rookie Award alongside Poland's 14-year-old Grzegorz Filipowski.

Then, in October 1982, Osada placed a close 2nd behind Midori Ito at All Japan Free Championships in Kobe, which was followed by a surprise 4th-place finish at the NHK Trophy in Tokyo, where she placed behind Katarina Witt, Rosalynn Sumners, and Tiffany Chin while finishing ahead of world medalists such as Claudia Leistner and Elizabeth Manley.

In her short program, she missed the triple loop jump in her combination, which only allowed her to pull up to 21st after this segment of the competition.

Although she won a couple of bronze medals at NHK Trophy, she was never able to regain her national title, nor was she able to make the Japanese world or Olympics team.