Toshiko Sato

Toshiko Sato (1975— ?) ("Tosh" to her friends) applied her scientific skills to the Torchwood 3 team, after having worked for UNIT. Beautiful, brilliant, yet insecure, much of Tosh's private life remains a mystery.

Early life
Toshiko was born in London]. Her parents moved to Osaka, Japan, in 1977, then back to the UK in 1986 (when speaking Japanese she does not have a noticeable Osakan accent, however). Her Japanese-born grandfather (born 20th January 1920) was a decoder at Bletchley Park and her parents were in the RAF.

Later life
Toshiko graduated with distinction from university in 1995. (source?) Around 2003 (TW: Fragments), though possibly in 2005 (TW: Greeks Bearing Gifts), Tosh worked at the Lordmoor Research Facility, run by the Britsih Department of Defense. Blackmailed, with her mother's life in jeopardy, Tosh stole the plans to make a sonic modulator and successfully built one, even though the plans really shouldn't have worked. She was arrested by UNIT and then saved by Jack Harkness. He complimented her on making a functional design of the schematics available to her, and offered her a job with Torchwood as an alternative to spending the rest of her life as a prisoner in a UNIT holding cell. (TW: Fragments).

Life with Torchwood
Every year for a day, Torchwood 3, had woken up Tommy Brockless a young World War I veteran frozen in 1918. During the four years that Toshiko had been working for Torchwood she developed a crush on him. (TW: To the Last Man)

Toshiko met the Doctor in spring 2006 while examining an "alien pilot" in the mortuary at Albion Hospital. She was slightly hurt when the creature turned out to be alive. She was referred to as "Dr Sato". (DW: Aliens of London)

Tosh always found Owen attractive. Despite this, Tosh had a lesbian affair, her first homosexual experience, (torchwood.org.uk) with "Mary", a female alien who tried to use their relationship to gain access to her technology, which Torchwood had previous confiscated. In order to gain Tosh's confidence the alien allowed her the use of a pendant which granted her the temporary power of telepathy. Tosh used the device to save the lives of a woman and her child, about to be murdered in a domestic incident, but she became suspicious of the device when its use gave her insight as to how her team mates regarded her. After the defeat of her former lover, Mary, she decided to destroy the pendant, fearing what consequence such a device could have for humanity. (TW: Greeks Bearing Gifts)

Later, during one of Tommy Brockless' yearly awakenings, the past and present time shifts began occur, which the uniformed thought of as "ghosts". To prevent a temporal catastrophe, Tosh and the team saw to it that Tommy returned to 1918, after the couple had a short sexual relationship. (TW: To the Last Man)

She fell in love with Adam Smith when he gave her memories that they were in love and when she was told this she still couldn't bring herself to take the retcon pill until she realised it was the right thing to do. (TW: Adam)

Toshiko was personally responsible for shutting down the Pharm. By that time she had actually taken the initiative to ask Owen, with whm she had feelings, out on a date. She was extremely saddened when Owen was fatally shot in the chest by Aaron Copley. (TW: Reset) After Owen's return to life via the resurrection gauntlet, she still maintained hope for a relationship, to Owen's disgust. (TW: A Day in the Death) Later, however, he seemed less negative about the idea. (TW: Something Borrowed)

Behind the Scenes
During her first on-screen appearances, in Aliens of London, Tosh seemed to work for UNIT. (Russell T. Davies had yet to come up with the idea of the Torchwood Institute.) However, given what we now know of her history, that seems plausible, though still possible. It also seemed apparent at the time that she had medical, rather than technical background.

Key Life Events

 * Jack Harkness recruits Toshiko to join Torchwood 3. (TW: Fragments, flashback)