Sasha was Riff's girlfriend from 2000 to 2002, who first appeared in The Hunter. They met while Sasha worked at the UP-EX, delivering packages to Riff. She was generally known to be pleasant, without a temper, and Torg once said he thought she and Riff were perfect for each other.
In Spitting Image, Sasha helps Riff figure out the secret of Zoë's new tattoo. Later, when Torg was worried about Oasis stalking Le Snootier, he and Sasha went to dinner there, and sure enough Oasis found them, proving that Oasis was still looking for them and a danger to Zoë (see Not a Good Idea. Torg and Zoë went to Le Snootier in The Love-Potion: PART 2).
She appears sporadically at various points points, notably in The Great House War, where she helps in the epic Bun-bun snowball fight, and Shadow Boxing, where evil moths eat everyone's clothes. Then during Dangerous Days Ahead (chapter), it comes out that someone in the house is leaking information to Hereti-Corp. At first Torg assumes it's Sasha, but Riff confesses, leading to a falling out between Riff and Torg. Riff realizes he needs to deal with Hereti-Corp, so he breaks up with Sasha preemptively, presumably to keep her safe. That doesn't work, though: she's kidnapped by Hereti-Corp, along with Torg, Gwynn, and Bert. Riff breaks into the compound to rescue them, but Sasha is badly injured by Cloney in the ensuing fight. Eventually they all escape, and Sasha is taken to a hospital.
After the Cloney fight, Sasha moves away, leaving only a box for Riff with some belongings and a DFA remote (BLEEP on Earth). She isn't heard from again until bROKEN, seven years later. When Riff uses the DFA to escape from Oasis, Torg finds Sasha to help him find them, and the possibly dead Zoë (Picking up the Pieces).