Tifa
Tifa Lockhart is a character in Kingdom Hearts II. She originates from Final Fantasy VII. Her look in Kingdom Hearts II is modelled on her look in the film Final Fantasy VII: Advent Children. She is voiced by Ayumi Ito in the Japanese and Rachel Leigh Cook in the English version.
Biography
Tifa appears during one of Sora's visits to Hollow Bastion in Kingdom Hearts II, inspecting Ansem the Wise's study, looking for "a guy with spiky hair," but not elaborating any further. She posesses the same tremendous strength she did in Final Fantasy VII, easily capable of high level martial arts such as lifting a gigantic portrait of Xehanort, and kicking a wall hard enough to shake a whole room (her high physical strength being displayed in a comical way is small running gag).
The person she's looking for turns out to be Cloud Strife, and she almost catches up to him during the Heartless invasion, but he chases after Sephiroth, leaving her fight a large group of Heartless on her own. She is later the third person to fight alongside Sora in the Ravine Trail, preceeded by Yuffie and Leon, and followed by Cloud.
Tifa finally catches up to Cloud just as his confrontation with Sephiroth reaches its climax. She tries to help Cloud, saying that all that needs to be done is to surround him in light, and telling Sephiroth that the darkness will always be there, but in a place that he can't reach. She fights with Sephiroth very briefly, but he and Cloud disappear once again, leaving her to continue the pursuit.
If Sora wins the optional Sephiroth boss fight, Tifa will give him the Fenrir Keyblade. Cloud and Sephiroth are the only Final Fantasy VII characters she interacts with, she never meets with Aerith, Yuffie, or Cid.
Olympus Coliseum
Tifa appears in Olympus Coliseum as a boss in the Hades Paradox cup. During round 10, she teams up with Yuffie, despite having not been shown to encounter her outside the tournament. During round 25, she fights alongside Cloud. Her last fight is in round 49, where she is partnered with Cloud, Yuffie and Leon.