Natasha noticed that Weyland Industries was doing a lot of business with an international organization named Cronos. She decided it was good measure to see what goods the two mysterious entities were exchanging in a warehouse off of the docks. Inside the shipping containers were things that Natasha simply thought were outright disturbing. The contents she found included human organs and remains. Other containers seemed to be filled with what looked like animal body parts, but the original species of which she could not identify.
Something in her xenomorph senses told her that there was still more to see within these containers. With her enhanced sense of smell she could tell that there was a man-sized (albeit large) intruder in one of the containers, and it didn't feel very much at all like a human.
She decided to tear open the container to see the stow-away first hand. What she found was a seemingly insectoid man with an impressive amount of firepower. The Guyver.
Both of them made the faulty assumption that the other was working with his or her enemies. Xeno-girl would attempt to spit acid only to find that the Guyver could quickly recover from the wounds. The Guyver would find that the nimble Xeno-Girl could dodge even the highly precise forehead laser. However, there was something about her that told him that she wasn't out for blood. The Guyver held back from using his devestating Mega-Smasher and instead discharged the Guyver suit revealing the 17 year old Japanese high school student Sho Fukamachi.
Natasha was taken off guard by such a move of trust. She pulled back her own bio-suit to reveal her face. Something told each other that they were going to have many good times at their enemies' expense.