The plot, which takes place between the events of Tekken 5 and Tekken 6, begins with Anna Williams setting up a decoy for her sister, Nina Williams, who is currently working with the new head of the Mishima Zaibatsu, Jin Kazama. Anna, on the other hand, works for Jin's father, Kazuya Mishima and its rival organization, G Corporation. Both are seeking information about a student named Shin Kamiya, and Anna dispatches as a Chinese student Ling Xiaoyu to act as a spy, while Jin sends humanoid robot Alisa Bosconovitch for a similar purpose.
During their investigation, Xiaoyu and Alisa form a friendship, although they are forced to turn against one another when Shin is captured by an unknown assailant. It is here that Alisa is revealed to be a robot - although Alisa believes she possesses human qualities after she spares Xiaoyu's life. After coming to terms with each other, Xiaoyu is abandoned by Anna and G Corporation, and the two girls flee from their previous organizations, taking refuge in their teacher, Lee Chaolan's mansion.