Reileen Kawahara is the sister of Takeshi Kovacs.
Reileen was born on Harlan's World and is of mixed Japanese and Eastern European decent. She has one older brother, Takeshi Kovacs. During their childhood, Takeshi was forced to kill their Father after he threatened to kill Reileen. Taken into care, Takeshi joined the Colonial Tactical Assault Corps on the understanding that his sister would be taken care of. Instead, Reileen was sold to the Yakuza and became one of their enforcers. During a CTAC raid, Reileen met Takeshi for the first time in years. During the reunion, CTAC officers tried to kill Reileen, prompting Takeshi to turn on them in defence of his sister. Reileen did the same for Takeshi, turning on her Yakuza masters.
Both fugitives, Reileen and Takeshi fled to the wilds of Harlan's World, falling in with Quellcrist Falconer and her Envoys. While Takeshi became dedicated to the cause, Reileen was less enthusiastic.
Throughout the series
Reileen personifies the worst traits of a meth, and all the qualities that Quellcrist Falconer warned about. She is arrogant, manipulative, self centered and with a massive ego and a "love" for her brother that verges on the psychotic. She believes she has made herself stronger and better by getting rid of things she sees as weak- mainly empathy, compassion and human emotions. She is somewhat ignorant in certain matters- she claims to love her brother, but does not seem to grasp what love means and the bonds that it can form.
Reileen Kawahara, in the book the series was based on wasn’t Kovacs’ sister. Hence their different surnames.