Nuriko first appears disguised as "Kourin" in Emperor Hotohori's harem, a place Hotohori seldom visits except to welcome new maidens. "Kourin" was actually Nuriko's younger sister, who passed away at a young age. To keep her memory alive, Nuriko began imitating her behavior and appearance. Born in Eiyou, the capital of Konan, Nuriko has superhuman strength, which is further enhanced by a pair of bracelets that transform into armbands by Taiitsukun. He is 18 years old and his real name is Ryuuen Chou, named after the star Willow.
Though prone to jealousy, quick to anger, and somewhat calculating, Nuriko is also level-headed and compassionate, showing deep concern for Miaka and Tamahome's relationship. As "Kourin," he is infatuated with Hotohori, but as a man, he also harbors feelings for Miaka Yuuki. Initially jealous of Hotohori's affection for Miaka, Nuriko eventually becomes her close friend. After confronting the pain of losing his sister Kourin, Nuriko realizes he had been living as she would have, not as he wished. This revelation allows him to embrace life as a man. He cuts his long braided hair and confesses to Tamahome that he loves Miaka more than just a friend.
Despite maintaining his feelings for Hotohori, Nuriko decides to stop dressing as a woman to better protect Miaka. Throughout the rest of the series, even after his death at the hands of Ashitare, one of the Seiryuu warriors, the bond between Nuriko and Miaka remains strong. Nuriko is the first of the seven Suzaku warriors to die.
In Fushigi Yuugi Eikoden, Nuriko is "reborn" as a young girl named Ko Keishun in a local marketplace. She steals Tasuki's magic ball and breaks it. Despite her small size, she lifts a heavy rock, revealing herself as Nuriko's reincarnation. In the episodes leading up to his death, Nuriko reveals that he had fallen in love with Miaka.
