"Tekken 5: Dark Resurrection (Tekken: Dark Resurrection for the PSP version) is an update to Tekken 5 and is technically the seventh game in the Tekken series. The Arcade version was released in Japan in 2005 and in North America in 2006, while the PSP version was released later that year. The game was also released as downloadable content on the PlayStation 3 via the PlayStation Network online service in 2007."
"The game follows exactly the same storyline as Tekken 5, only with the additions of Lili Rochefort, who seeks to destroy the Mishima Zaibatsu and end her father's financial problems, Sergei Dragunov, a member of Spetsnaz who has been sent to capture Jin Kazama, and Armor King, who was thought to have been killed before the events of Tekken 4."
Source: Wikipedia, "Tekken 5: Dark Resurrection," available under the CC-BY-SA License.