Soraya joined Squaresoft as a graphic designer in the early 1990s through an advertisement in ASCII computer magazine. Soraya was a graphic designer at Squaresoft for Romancing SaGa, Final Fantasy V, Final Fantasy VI, and Final Fantasy IV: Easy Type.) She helped create the characterization for Final Fantasy VI characters Edgar and Sabin, beginning by choosing two playable character classes, in this case monk and machinist, choosing the desert as a setting, and then creating an extensive character background in a private booklet for herself.
Soraya and her husband Tetsuya Takahashi submitted a script for Final Fantasy VII which was called "too dark" and "complicated" for a fantasy game, but were allowed to start a new project based on the script, which was worked into a full treatment with cutscenes, eventually being released under the name Xenogears. The story was inspired by the writing pair's interest in Jung, Nietzsche, and Freud, addressing questions of "where do we come from, what are we, where are we going". Soraya and Takahashi went on to write the plot of Xenosaga Episode I, Xenosaga Episode II, Xenogears, and Xenosaga Pied Piper. Xenosaga's use of many biblical references and the influence of other religions reflected Soraya's interest in belief and its power. KOS-MOS was designed by Takahashi, reflecting a reversed view of human construction, giving the character a powerful body and fragile soul. Several designs that were not used were created by designers Kunihiko Tanaka and Kouichi Mugitani. Originally intended to be six games, the series was cut short, and many plot points had to be changed and moved because of the second episode's plot.
- Final Fantasy V (1992): map design
- Final Fantasy VI (1994): field graphic designer, script
- Romancing SaGa 3 (1995): graphic designer
- Xenogears (1998): scenario writer
- Xenosaga Episode I: Der Wille zur Macht (2002): event scenario writer
- Xenosaga Episode II: Jenseits von Gut und Böse (2004): assistant author
- Xenosaga: Pied Piper (2004): script co-author
- Soma Bringer (2008): scenario