Noike Kamiki Jurai, originally born Noike Sakazua, is a central character introduced in the third OVA series of Tenchi Muyo! Ryo-Ohki. She is the adopted daughter of Seto Kamiki Jurai, a powerful and manipulative figure within the Jurai royal family. Noike's early life was marked by abandonment: her wealthy father left when her mother became pregnant, and after her mother found a new partner who did not want a child, she was placed in an orphanage. This history of rejection shaped Noike's personality, making her practical, resourceful, and determined to prove her worth. Despite her difficult start, she was later adopted by Seto and became a member of the Jurai royal household, bonded to a third-generation Juraian tree ship named Kyoko. Kyoko was secretly modified to possess power equal to a second-generation tree, a precaution born from past threats to Jurai.

Noike serves as a first-class detective in the Galaxy Police and was once the partner of Mihoshi Kuramitsu. Her experience in the orphanage gave her the ability to handle Mihoshi's scatterbrained nature with firmness and occasional sternness. She also received medical training, which she later uses to care for Tenchi when he falls ill. As part of Seto's scheme, Noike is sent to Earth under the guise of being Tenchi Masaki's arranged fiancée. Her true mission is to observe Tenchi and the extraordinary women who have gathered around him, including Ryoko, Ayeka, Sasami, Mihoshi, and Washu, as they represent an unprecedented concentration of power. Initially unhappy with the situation, Noike eventually sneaks away from her escorts and meets Tenchi by chance while he works in the carrot fields. She then settles into the Masaki household, quickly proving herself capable: she helps Sasami with cooking, cajoles Ryoko and Ayeka into doing chores, and even purchases a pickup truck to assist with farm work. She also cuts her long hair short, reverting to a style from her younger days, though she wears a wig for official occasions.

Noike's motivations evolve from following Seto's orders to genuinely caring for Tenchi and the household. She develops romantic feelings for him, though the engagement was originally a ruse. Throughout her time on Earth, she is plagued by strange visions of Tenchi with a young girl, which cause her to faint on several occasions. These visions are later revealed to be the lingering presence of the female half of Kagato, an entity originally created by Washu as a hermaphrodite but later split. This female half was sealed by Dr. Clay and implanted within Noike's body, allowing the antagonist Z to spy on the Masaki household through Noike's eyes. After the threat is discovered, Washu removes Clay's seal, and the female Kagato fully merges with Noike, resolving the visions and integrating the fragmented consciousness.

Noike's key relationships include her adoptive mother Seto, who orchestrated her mission, and her former partner Mihoshi, with whom she often displays impatience. She treats Tenchi with respect and growing affection, and she maintains a practical, no-nonsense dynamic with Ryoko and Ayeka, managing to mediate their rivalries. Her ability to keep the household running smoothly and her willingness to help in any task make her an indispensable presence. In terms of notable abilities, Noike is a highly capable detective and investigator, proficient in medical care, and skilled at driving both terrestrial and Juraian vehicles. As a bonded Juraian royal, she commands the ship Kyoko, which possesses a remote interface unit that allows for direct interaction. Kyoko itself is described as attention-seeking due to its isolated development. Noike's role in the story is that of an observer who becomes a full participant, transitioning from a spy into a trusted member of Tenchi's family, and her development centers on overcoming her past abandonment and finding a place where she is valued and loved.