Ling Xiaoyu was introduced in Tekken 3 and has returned in every subsequent release. Xiaoyu was born and raised in China, and is a student at Mishima High School (a school owned by the Mishima Zaibatsu), where she was a schoolmate of Jin Kazama.
She strongly hinted to have a crush on him due to her tekken tag ending in her school outfit , and her Tekken 4 prologue wishes to be reunited with him. Her Friend Miharu is aware of Xiaoyu's feelings for Jin.
Ling Xiaoyu's dream is to be able to build her own amusement park, and upon learning that the Mishima Financial Empire is rich and powerful, she seeks out Heihachi Mishima (President and CEO) to make her dream a reality. While on a vacation in Hong Kong, Ling saw a yacht bearing the name, "Mishima Financial Empire". Ling found her way on board, only to discover that Heihachi was not on the ship. However, Ling was discovered shortly after the ship left port, and this was reported to Heihachi immediately. When Heihachi arrived, he found all of his men unconscious, and when he found Ling, she threatened that she would go berserk again if he did not accept her challenge. Heihachi, amused by the young girl, promises to build her the amusement park of her dreams, if she can win The King of Iron Fist Tournament 3.
In her non-canonical ending movie, we see a bright and colorful amusement park titled "Xiaoyu Land", with Xiaoyu and her pet Panda riding on a roller coaster, merry-go-round and going shopping. We then see that this is Xiaoyu's day dream, with Heihachi about to unveil the real amusement park. Upon Heihachi turning all the lights on, we see a dark, somewhat bland amusement park titled "Heihachi Land". Heihachi begins to burst out with laughter, until Ling attacks him, with the word "JERK!" appearing on the screen. Ling is also the granddaughter and student of Wang Jinrei.
Ling was a junior at the Mishima High School, where she lived, studied and trained. Lacking any particular goals, Ling grew tired of her everyday routines. However, one day she received a mysterious e-mail that warned her that Heihachi had evil intentions and that her life is in danger. Although she replied to the e-mail, she received no more e-mails from the anonymous individual. Ling's best guess that Jin, who had been missing since the last tournament, could have sent the message. Ling believed the message and became increasingly suspicious of Heihachi and the Mishima Zaibatsu, and upon the announcement of The King of Iron Fist Tournament 4, she decided to enter, hoping to be reunited with Jin and to unveil the truth behind Heihachi and the Mishima Zaibatsu.
In Ling Xiaoyu's ending video (which is once again non-canonical), we see that she won the tournament and has taken over the Mishima Zaibatsu. She was successful in unveiling the truth behind Heihachi and the Mishima Zaibatsu, discovering that they were behind the raid of G Corporation. Ling's friend, Miharu, visits her in her office and admits to Ling that she has flunked all of her college entrance exams. Ling then offers her a job, and goes on to say that she saw Jin Kazama after the tournament, and that he told her that "[she] has all of these dreams, and [she] should make them happen for herself". Xiaoyu then tells Miharu that she wants the two of them to build her theme park together.
Ling is a student at the Mishima High School, who, due to her friendship with Jin Kazama, is on a mission to save the Mishima family. During the last tournament, Ling was saved from Heihachi and his evil plans by Yoshimitsu, who taught her the history of the Mishima family. Hearing this, Ling came to the conclusion that the root of the misfortune surrounding the Mishima family started with Heihachi's cruel upbringing of Kazuya (whom Heihachi tossed down a cliff as a child, as he thought that if he survived it and climbed back up the cliff, in the end it would make him stronger). When Ling heard of the death of Heihachi (who had been blown up when a group of Jack-5 robots attacked him, holding him down while one self destructed), she was greatly saddened. However, Ling happens to meet a brilliant scientist who claims that he can make a time machine as long as he gets the funding for development, and with The King of Iron Fist Tournament 5 about to begin, Ling decides to enter in order to fund the development of a time machine.
After winning the tournament (again, her ending is non-canonical), Ling Xiaoyu successfully raises the money needed to develop the time machine, and is the first to use it. She travels back in time to when Heihachi was about to throw Kazuya off a cliff, with the intention of averting this event that would go on to tear the family apart. Unfortunately, Xiaoyu lost control of the time machine and barreled into Heihachi and Kazuya, knocking Kazuya down the cliff, while Heihachi is nearly sent over himself. Xiaoyu returns to the present time and is miserable about her failure. The scientist emerges, laughing, and tells her that nobody can change the past, and that "The best you can hope for are minor improvements".
When Xiaoyu heard that Heihachi had not died, she breathed a sigh of relief. However, the new head of the Mishima Zaibatsu, Ling's former schoolmate, Jin Kazama, aims to take Heihachi's life. Xiaoyu attempted to stop Jin herself, but the Zaibatsu pushed towards militarization, making it difficult to get anywhere near Jin. The Mishima Zaibatsu's declaration of its independence and of war drew hostility from around the globe. When The King of Iron Fist Tournament 6 is announce, Ling enters in hope that she can save Jin's soul from evil.in her ending "Romantical dreams"
Xiaoyu confronts Jin, just as he is about to jump off the rooftop of a building. She tries to dissuade him from doing so, only to get the reply of "The evil that I've (Jin) perpetrated....can never be undone". Xiaoyu shook her head and ran up to Jin, embracing him, vowing that she would "stand by you". Apparently moved by this, he thanks her.....
In the end, however, it was revealed to be only a dream, as Xiaoyu was then seen sleeping on Panda, unaware that the latter was uncomfortable and that she was still in the throes of her dream...until she hugs Panda very tightly, causing the latter to toss her off the side of the bed.
Awaking, Xiaoyu was still confused to where she was....
- Xiaoyu is an unlockable character in Smash Court Tennis Pro Tournament 2.
- Xiaoyu is also the shortest female character in the Tekken Series.
- Xiaoyu's Tekken 3 and Tekken 5's endings are the only ones in the series to use both CGI and animation.
- Xiaoyu is a distant relative of Wang Jinrei.
- Xiaoyu is also tutored by Heihachi Mishima and enrolled her to the Mishima High School.
- Xiaoyu was saved by Yoshimitsu during Tekken 4.