In the light novels, it is mentioned that her father and younger sister live in New York. Her mother died of cancer roughly 4 years before the start of the series. Shortly after that Kaname ran away from home but returned the next day. Kaname's relationship with Shizu, her late mother and Ayame, her younger sister, is apparently friendly, but she is more tense towards her father, Shunya, who works for the United Nations as its environmental High Commissioner. Her late mother's family also seems to have strained relations with the Chidori family, at least until her grandfather from that side makes amends. Because of her sensitive past, she developed a tough-lady attitude, which has helped her deal with her past and survive several life-threatening situations. In the novel A Dancing Very Merry Christmas and in the Full Metal Panic! Anime Mission fan book, it is also revealed that she shares her birthday with Tessa on December 24, 1984 (Christmas Eve).
Kaname lives alone in her own apartment across from the complex which Sousuke lives in. She takes on multiple part-time jobs and sometimes invites friends to join her, which often ends with a catastrophe because of Sousuke. She began attending Jindai High School at the age of 15 and is currently in her second year. She leads a normal lifestyle and is the class representative and vice president. She is quite popular at school. However, after Sousuke is transferred to her class, her life is turned upside down and she becomes involved in various Mithril operations.
Kaname's bravery and determination came to a head in the climax of the novel Continuing on My Own. Following Sousuke's defeat by the hands of Leonard Testarossa, she gives herself up to Leonard and Amalgam to save his life. As she is picked up by the Belial's giant hand, she whispers something to Sousuke before being whisked off. After being taken by Leonard, she is imprisoned by Amalgam at an island villa. In the novel Come Make My Day, Sousuke arrives at the island in order to save her, but is unable to do so as she is taken away in a helicopter.
In the most recent novel, Semaru Nick of Time, the origin of the Whispered is revealed to be caused by an accident during a Soviet experiment using an Omni-Sphere that occurred on December 24, 1984, when all the Whispered were born. Leonard Testarossa takes Kaname back to the Omni-Sphere after recovering from wounds in Come Make My Day. She is then forced to resonate with Sophia, a key Whispered, who overtakes Kaname's personality. Under Sophia's control, Kaname is shown the illusion of shooting and killing Tessa and Sousuke, and then leaves with Leonard for Merida Island, where Amalgam has built a machine to utilize the final ability of the WhisperedLink title