Toshiko Sato's mother, like her father, belonged to the RAF. (TW: Greeks Bearing Gifts) She suffered racial prejudice during World War II. (TW: Captain Jack Harkness) She gave birth to her daughter in London in 1975. (TW: Greeks Bearing Gifts) In 2005, she was kidnapped circa 2005 by Milton as a hostage as a way for Milton to get her daughter work on a sonic modulator. Milton tested out the sonic modulator on her. (TW: Fragments) A vision (perhaps induced by Bilis Manger) of her mother with blood running down one side of her face urged Toash to turn against Jack with the rest of the team and open the the Rift. (TW: End of Days)
- Her fate remains unknown. However it seemed implied that she died.