She was the official representative for Japan at the Miss Universe 2008 pageant which took place in Nha Trang, Vietnam on July 14, 2008. She made the first cut by advancing to the top 15 finalists competing in the swimsuit round, and was ultimately placed in 14th position, being the highest placed Asian delegate to make the cut.
Hiroko Mima was trained for the pageant by her national pageant director Ines Ligron, who also took Korea’s candidate Sun Lee under her wing. Mima continued Japan’s stake in the Miss Universe pageant by placing in the semi-final for a consecutive third time, despite not being favoured by numerous pageant sites as a potential semi-finalist.
Hiroko was the first contestant in the history of Miss Universe to wear a purse during the evening gown portion of the presentation show. In 2009, Mima placed in the Globalbeauties.com top 32 Grand Slam Beauties. Mima has recently trained and prepared Emiri Miyasaka for Miss Universe 2009. Now, She Is The new National Director for Miss Universe Japan.