Yuuji's elder sister. Despite her delicate and diminutive body, she is brilliant and excels in almost everything, and due to that, she can be called a genius. She is the same age as Amane. They went to the same school, “Takizono Private Academy,” and were on the school's basketball team. She apparently died in an accident which greatly influenced Yuuji and Amane's lives. [From Shiori-chan's review] Presumed dead in a tragic accident years earlier, she was secretly recovered by a covert government research facility, which sustained her life to harness her intellect as the core of the Thanatos System, an advanced computer designed to replicate and manage human brain data. Kazuki was selected to be the blueprint for this groundbreaking system. Despite the extraordinary circumstances surrounding her existence, Kazuki's tender affection for her brother remains steadfast. [Edited from Le Eden de La Grisaia - Visual Fanbook]