Hara started her career as a junior idol under the name Mai Nanami. As a teenager, she sang the theme song Spicy Days for the animated TV show The Marshmallow Times on TV Osaka in 2004. She also had parts in two movies in 2005, the March TV drama The Dream of Delinquent Boys for TBS, and the April theatrical release, horse-racing melodrama Lovely Fields which was later released as a DVD.
She had also made a bikini-model photobook, Mai Nanami First Photobook, in May 2005 and a non-nude (gravure) DVD titled Mai Nanami: Yamagishi Shin Digital Movie Museum which was released in August 2005. As Nanami, she also played the female lead in another mainstream movie that was due to be released in Japan in 2006 but had its debut at the American Film Market in Santa Monica, California in November 2005 as Deep Sea Monster Reigo. The film was eventually released in Japan as Reigo: The Deep Sea Monster vs the Battleship Yamato.
After a long hiatus, she re-emerged as Saori Hara in August 2008 and appeared in a non-nude gravure video titled Clear Water. The next month, in September, she posed nude for the first time in the Japanese men’s magazine Sabra, and it was announced that she was contracted to the Soft On Demand (SOD) adult video studio.
She became the face of the SOD group in its anti-STD campaign in November 2008, a role formerly played by long-time SOD AV actress Nana Natsume. Hara’s her first adult video (AV) was released by SOD in January 2009 with the title Real Celebrity Saori Hara: Miraculous AV Debut and was reported to have sold 100,000 copies.
About the same time as her AV debut, Hara posed for a set of nude photos set in Tokyo public places by photographer Kishin Shinoyama which was published January 28, 2009 by Asahi Press as NO NUDE by KISHIN 1 20XX TOKYO. Shinoyama has said that he likes working with porn stars because they have no problems with nudity. However, both Shinoyama and Hara were charged by Tokyo authorities with public indecency.
Her May 2009 hamedori adult video for SOD, Real Celebrity Saori Hara: Brown Eyes, directed by Company Matsuo, had the quarter-German Hara traveling to Germany for six days to explore her roots. The SOD studio celebrated the end of Hara’s first year with the company with the four hour cosplay video, Real Celebrity Saori Hara: 8 Changes and Sweet Sex, where she plays eight different characters.
On December 11, 2009, Shueisha published Hara’s autobiography titled My Real Name Is Mai Kato: Why I Became an AV Actress. The 144 page book details Hara’s upbringing and family life, her views on sex and her career as a teen idol and eventual AV idol. Her book is one of a number of autobiographical publications by actresses about the AV industry going back Ai Iijima’s million-selling Platonic Sex and including Mihiro’s partially fictional May 2009 work Nude and Honoka’s tell-all Biography of Honoka: Mama, I Love You published in January 2010, marking a trend in which the AV industry is losing its stigma and being assimilated into Japanese popular culture.
Hara continued her AV career with SOD in 2010 including the January release Real Celebrity Saori Hara: 22 Years Old – Awakening Sexual Desire and the August SOD Star x SOD Cinderella – Mega Gangbang where the plot revolves around “veteran” SOD actresses being paired against newcomers.
She was the winner of Adult Broadcasting Award for Best Actress in March 2010 for her 2009 appearances on adult channel Midnight Blue.
Hara’s presence in mainstream films was maintained in 2010 with her role as an aromatherapy client in Yumiko no Aroma, which debuted at the Yubari International Fantastic Film Festival in February and was released theatrically in May.
According to an article in Shukan Post,Saori Hara and Maria Ozawa are the two most downloaded AV actresses in China.
Hara’s appearance in the much-publicized movie “3D Sex And Zen: Extreme Ecstasy” has shot her to fame worldwide.