Born in Kanagawa Prefecture, she made her senior international debut at the 2006 IAAF World Cross Country Championships and although she finished in 19th place, this was enough to help Japan to the women's team bronze medal.

[1] She struck team bronze the following year, this time in the 2007 IAAF World Road Running Championships where she finished 13th overall and ran a half marathon personal best of 1:09:26 hours.

Ozaki opened the 2008 season at the Kagawa Marugame International Half Marathon and she came close to her personal best (1:09:30) to take second place behind Philes Ongori.

[7] She ran at the Yokohama Women's Marathon in February 2011 and broke the course record with a time of 2:23:56, gaining herself a place in the Japanese World Championship squad in the process.

[10] She secured a place on the Olympic team with a strong performance of 2:24:14 hours at the Nagoya Marathon, where she was the first Japanese and runner-up behind Albina Mayorova.