Being fifteen years old, Tifa was born at about the same time the war ended. She was born on Earth, and because of that, the Space Rebellion stubbornly denies her power, stating that anyone who was born in space is automatically a Newtype, but those from Earth are likewise automatically Oldtypes who have not yet evolved as only living in space can enable one to.

Tifa is an invaluable part of the Freeden, directing the ship where to go during their search for more Newtypes and often warning the crew of impending danger. She grows especially close to Garoad, and through her feelings for him, she eventually becomes less introverted and begins to act more normally by doing such seemingly simple things as eating with the rest of the crew instead of alone in her room. However, when she and Garoad begin to grow apart, her powers weaken, and it's not until he reinforces their bond that she completely recovers her abilities.

Her power to see into the minds and hearts of other people never ceases to amaze those around her. When the New Federation sends a group of sabatours to the Freeden, Tifa immediately senses their intentions and then warns the rest of the crew. However, when things go awry, the sabatours escape, leaving only their leader, who had planned to die on the battlefield so that he could meet his dead wife again. And what does Tifa do? She runs out into the middle of the fight, grabs the man, and tells him that he mustn't die because he's a kind person.

She knows who her true allies and enemies are. She trusts Lancelow because she knows he's a good person; however, she doesn't trust Zidel, because she knows the opposite is true for him. When she and Garoad are captured by the New Federation, Garoad bargains with Bloodman for the release of the Freeden's crew in return for information on the Space Rebellion. Tifa realizes he has no intention of releasing their comrades, she refuses to help them out.

She also has the ability to show others the "truth," as we see when she shocks Caris by telling him that she's a natural Newtype, not an artificial Newtype like he is. Caris had been told she was artificial, and he soon after realizes that he was just being used so that the Space Rebellion forces could use their giant mobile armor to attack the Earth, due in part to the effect Tifa had on him (though to be fair, the direct cause was when he felt Nomoa Long's heart).

It is with Tifa and Tifa alone that the crew of the Freeden, as well as Lancelow, Bloodman, and Zidel are able to contact D.O.M.E. on the Lunar surface. The meeting with D.O.M.E. explained exactly what a Newtype was. The disputed definition was the cause of a potentially catastrophic war that would repeat the mistakes of the war fifteen years earlier, so Tifa's meeting with D.O.M.E. held a bit of significance for the people of the After War world.

Finally, Tifa has absolute faith in Garoad. When the two are originally trying to escape the Freeden, she trusts Garoad enough to let him hold her in the GX's hand as a "shield," because he knew that Witts and Roby couldn't fire, and she knew that Garoad would never put her into danger. Their bond eventually grows so strong that, as mentioned before, her abilities actually begin to weaken at one point when the two of them drift apart.