Born as Annika Hansen in Tendara Colony in 2348 to Magnus and Erin Hansen, a pair of ethologists, Seven of Nine was assimilated at the age of six on the USS Raven. The Borg Collective was all she knows, and what provided her with a sense of order. After serving as a representative of the Borg during a Borg-Voyager alliance, Seven was disconnected from the Collective in the Star Trek: Voyager episode "Scorpion" by Captain Kathryn Janeway, Commander Chakotay and Chief Engineer B'Elanna Torres in order to prevent Seven's betrayal and an ensuing assimilation of the USS Voyager.
Following her disconnection she found in Captain Janeway a mother figure who helped her in becoming more human with each episode. The Doctor also provided valuable guidance in enabling her to develop her social skills and thus "blend in" with the crew of Voyager. Her character took an unexpected twist in the final episodes of the series: she falls in love with Commander Chakotay and is set to marry him as the series closes. At the end of Voyager, Seven had a surgery to one of her implants to allow her to use emotions.
While Seven proved popular with many of the show's fans, there was some criticism that the show began to focus too much on her character to the exclusion of others. Some also considered her tight-fitting costume to be too blatant an attempt to appeal to the young male demographic.