She knew Pavel Chekov from when they had served together on the Enterprise during its second five-year mission under James T. Kirk. She then transferred to the Invincible, commanded by Captain Philip Styles.
Styles was known for being very "by-the-book" -- he would issue demotions where other commanders would have issued commendations. For example, Kazanga was promoted to lieutenant commander twice -- and busted back to lieutenant twice -- by Styles.
By 2275, Lieutenant Kazanga had become assistant chief of security on USS Reliant, commanded by Captain Clark Terrell. She was reunited with Chekov here, where he was the newly-minted executive officer. (Orion Press: "The Blue Rose", "Like You and Me")