Panda

Panda trains with Xiaoyu. Panda was introduced in Tekken 3, and she has returned for the rest of the current Tekken games. Kuma is in love with her,  however she hates him. Panda is a costume swap for Kuma in all of the Tekken games they have both appeared in. 
 

Tekken 3 

Panda's first appearance in the Tekken series. Panda is the protector of Xiaoyu and was cared for at Ling Xiaoyu's high school. When Ling wanted to participate in the Iron Fist Tournament she moved to the Mishima Industrial College in Japan. It was before this move that Heihachi learned Panda advanced bear fighting (the same as Kuma) so that she could serve as Xiaoyu's bodyguard whilst she was participating in the tournament. It was here that Kuma became fond of Panda, yet she keeps away from him due a strong dislike towards him. This is seen throughout some of the games when the characters are pitted against one another, for example in TAG Tournament there is a scene where Panda destroys flowerd given to her by Kuma. This is seen in Tekken 3 also when Ling Xiaoyu and Panda are leaving the building, Kuma is waiting outside the gate of Mishima Polytechnical School. Panda walks straight past him. 
 

Tekken TAG Tournament 

Panda is a playable character in the game, however TAG Tournament is not a part of the Tekken series canonical storyline. The game however allows players to see the bad relationship between Kuma and Panda.  
 

Tekken 4 

Panda accompanied Xiaoyu back to Mishima High School after the last tournament. She then spent her days training with Xiaoyu and wondering at times about Kuma's whereabouts who vanished after the tournament. At one point, two years after the latest torunament Xiaoyu told Panda about The King of Iron Fist Tournament 4, Xiaoyu expressed her concerns about the tournament to Panda, so Panda again decided to become her bodyguard.  
 
A scene is found in the game where Panda attempts to cheer up Xiaoyu by suggesting she tries to track down Jin. Xiaoyu's spirits are lifted when she realises that Panda cares however she decides that she must do it alone since she would be on the "endangered species" list. The desicion upsets Xiaoyu but she resolves that this is something she must do and decides she will do it alone. Panda hugs Xiaoyu as Xiaoyu utters to her that they will always be best friends. This scene is continued into the story that plays out for Panda in Tekken 5.     

 

Tekken 5 

Again Panda takes up the role of Ling's bodyguard in this game. After the ending of the King of Iron Fist Tournament 4, Panda realised that Ling had been feeling under the weather. Worried about her friend, Panda was searching within herself to find a way to cheer up Ling and decided that the easiest way would be to find Jin Kazama yet after various methods Panda was unable to track down Jin. However, one day Ling bursts into the room excited, telling Panda that she wished to take part in the King of Iron Fist Tournament 5. Panda had no idea why Ling wanted to enter the tournament but decided to be her bodyguard again hoping that this would help make her happy again.  
 
Panda's storyline is unchanged between Tekken 5 and Tekken 5: Dark Resurrection.
 

Tekken 6 

Panda is relieved to find that Heihachi Mishima is still alive but her relief is only brief when she hears of the announcement of the King of Iron Fist Tournament 6, bound by her duty she is again thrown into harms way.  Inher ending it is shown that Asuka yells at Lili, "Are you some sort of idiot?!" Then the two of them exchange powerful blows at each other. Meanwhile, Xiaoyu and Panda come rushing from the side, as the girl exclaims that she's going to be late. Panda runs faster and knocks away Asuka, Lili, and the limousine, who were all in the way. The two girls get back up and chase after Panda and Xiaoyu angrily.