Madoka Ozawa made her adult video (AV) debut at age eighteen with the video Pure Love for the Media Station Cosmos Plan label in December 1996. Another early work for the same studio was the January 1997 release 18 Dreams. Ozawa made several more adult videos for Cosmos Plan before moving on to another major studio, h.m.p, by October 1997. From early 1999, she also worked with Alice Japan and Atlas21 where she made Legend Of An AV Idol in May 1999. This was a documentary-style AV supposedly describing Ozawa's adolescence, her early sex-life, and the story of how she became an AV queen.

In 1997, she appeared in a mainstream movie, the Hong Kong sex comedy (also released as a DVD) Don't Tell My Partner, where she plays the sexy new girl in the office, "Nancy Lee". From 1997 to 1999, she also had roles in a number of direct-to-video V-cinema productions. More than one of her video performances was announced as her retirement from AV work. One such "retirement" AV was Fallen Angel X, which was released in September 1999 though she seems to have returned to the industry not long after its release. The plot of the video featured an "acrobatic" threesome and sex with an ex-boyfriend. The April 2000 release from h.m.p, Requiem, was also touted as Ozawa's farewell video.

This time Ozawa's retirement lasted for nearly a year and a half until she made a come-back with the Moodyz company video Indies AV Action in late 2001. She made a series of videos with Moodyz, and, in mid-2003, she also starred in a softcore gravure video, Look That Kill.

In December 2002, Ozawa visited Taiwan for the first time in order to attend an automobile exhibition as a gravure model. Her appearance at this event created such a stir with the public and media in Taiwan that she was invited for a second visit to appear before Taiwanese troops on Kinmen Island in 2003, the first time an adult performer entertained the Taiwanese military. Magistrate Lee Chu-feng welcomed Ozawa and predicted that her visit to the island would boost tourism. During this visit to Taiwan, Ozawa was invited to appear in the promotional campaign for Kaoliang Liquor and to serve as a model in a wedding dress show.

In February and March 2003, she was back in Taiwan participating in several entertainment and publicity events to heighten her public profile. She was offered opportunities to act in more TV dramas, film, and to release popular music albums. With this increasing offer of mainstream work in Taiwan, Ozawa officially retired from adult videos in 2003. However, her attempt to enter mainstream TV in Taiwan was not very successful.

Back in Japan, Ozawa's career was the subject of a three-volume Classic/Memorial series of videos from Cosmos Plan in 2004. Ozawa's final retirement video, released by Momotaro on April 30, 2004, was aptly titled Never Can Say Goodbye….