Childhood
Born in Eiyou, Konan's capital, Nuriko was the middle child of a cloth merchant. He had an
older brother and a younger sister, Kourin, with whom he was very close. In fact, because the two
were as close in appearance as they were in their relationship, many believed they were twins.
Unfortunately, tragedy was to strike them. When Nuriko reached the age of ten,
he was crossing the street, when his sister decided to follow him. She ran out into the road
and was hit by a horse-drawn cart. Because she was so young and the cart was going so fast,
she was immediately killed.
Nuriko blamed himself for her death, and thought it unfair that she had died while she was still so young. He thought there had to be a way to keep her alive, and to compensate for his part in the accident. So, he began to do his hair like a girl, and to wear lipstick and girl's clothing. He also assumed her name. To all intents and purposes, Ryuuen had become Kourin.
Yukigase
Six years later, Nuriko went to live with relatives in the village of
Yukigase. They all took him for a girl, because of his beauty and
his style of dress. As it turned out, that assumption was unfortunate
for him, as rumours of a Snow Demoness were circulating through the
village. This creature would only be appeased by the sacrifice of
the most beautiful girl in the village.
At the same time, the Emperor began a search for a bride. He demanded
the most beautiful girl from every village be sent to the palace. They said this girl would obviously
be able to escape being sacrificed. Every girl prayed to be chosen, but there were only
two candidates in the end - Nuriko and another girl, Byakuren.
Because he had saved her from Ashitare on the anniversary of Kourin's death
and because Byakuren reminded him of his sister, Nuriko made up his mind to
be the sacrifice to the Snow Demon and allow her to marry the Empress.
Unfortunately, even though Byakuren won the competition for most beautiful woman,
it was a trick by the elders. She was told to climb into a palanquin that would
take her to the palace. Because Nuriko had realised the elders' real intentions earlier,
he sprinted after the palanquin and took her place in it.
When he reached the mountain, he attempted to battle
the Snow Demoness by himself, but was hopelessly outmatched. At this point,
Byakuren, who had realised Nuriko's efforts in the beauty contest were not to
take her place as the Empress but to save her from the Demoness, appeared on
the scene. She distracted the Snow Demoness for long enough for Nuriko to recover,
but was critically wounded herself.
When the Snow Demoness was vanquished - the details are complicated
and not that important for this history - Nuriko returned to the village with Byakuren's
body. When the messenger came the next day from the palace, Nuriko went with him,
intending to live the life of Byakuren as well as that of Kourin.
Suzaku Seishi
For a year, Nuriko tried desperately to get Hotohori to fall in love with him. Sadly, his dreams of being chosen as Imperial Consort were dashed when Miaka appeared on the scene, as Hotohori fell for her. Nuriko was furious at being jilted, and sought revenge on Miaka. Even though he saved Miaka and Tamahome from a collapsed pagoda (proving himself to be a seishi), he tried to make the girl's life miserable. He treated her as her slave, sunk his claws into Tamahome and ultimately tried to drown her.
However, that changed when Miaka fell ill and the seishi had to take her to Taiitsu-kun - the only entity powerful enough to send her home. During that trip, Miaka accidentally discovered that Nuriko was a man, and, although she resolved to keep it a secret, her evil reflection had made no such promises.
Strangely, that revelation made the relationship between Nuriko and Miaka easier. Now that he was no longer pursuing Hotohori, Nuriko assumed the role of her big brother, protecting her and counselling her. Similarly, now that he had someone else for whom to care, he finally decided to let go of Kourin and to give up crossdressing for good.
Killed in the Pursuit of Being a Suzaku Seishi
After the seishi failed to call Suzaku the first time, they learnt that the ceremony could only be repeated if they retrieved the shinzaho (an object of power) from the country of Hokkan to the north. After Tamahome discovered that the shinzaho was hidden in a cave on top of Mount Black, they resolved to set out for it the next day.
That evening, Nuriko told Tamahome that he was in love with Miaka, but that he would not interfere in their relationship. The next morning, he provided proof of that promise when he volunteered to fetch the shinzaho while he and Miaka called the others. This, he reasoned, would give them time to work out their problems.
Unfortunately, when he arrived alone at Mount Black, he was attacked by Ashitare - the half-human, half-wolf Seiryuu seishi. He managed to defeat Ashitare, but was fatally stabbed through the chest in the process. As he was dying, he used what remaining strength he had to clear a boulder from the cave's entrance. Then, he collapsed in the snow. By the time Miaka and the other seishi arrived on the scene, it was too late and he died in her arms.
Restless Ghost
Though Nuriko had died, he was still an important presence in the final battle against Nakago. Taking over the body of the one of Nyan Nyan, he helped save Miaka from a falling building and defeat Seiryuu. Then, he returned to the book to be reborn, along with the other ghostly seishi.
Unfortunately, things did not go smoothly. The power of a devilishly-charming demon, called Tenkou, prevented any of them from being reborn. This demon wished to take over both the real world and the world in the book, becoming a god in the process. To stop him, they had to gather the seven memory-stones that would give Tamahome, who had been reborn in the real world as Taka, back his memory.
One of these stones was being kept by Nuriko's older brother, Rokou. Having lost both Nuriko and his little sister, Rokou was unwilling to part with the memory stone, as he said it was the one thing that linked him to Nuriko and he was afraid of letting go of it. Eventually, after a battle with a monster that had been planted inside of Taka, Nuriko persuaded him to relinquish the memory stone.
Once all the stones had been gathered and Taka had back his memories, they were able to defeat Tenkou. Nuriko again assumed the body of a Nyan Nyan to do her part. After that, they were able to be reborn.
Reincarnations
Oddly, there are two different possibilities given for Nuriko's reincarnation, and I would be more inclined to go with the first one, just because Drama CDs are generally a bit mad:
1) In the anime, she was reincarnated as a little girl, looking with extreme interest at the reborn Hotohori!
2) The Drama CDs gave another ending, where the Suzaku Seishi had been reborn in the real world. Nuriko was still a cross-dresser, and was tracked down by Tetsuya and Keisuke while they were in search of the seishi's reincarnations. After initial misunderstandings, Keisuke called Miaka, and her voice brought back Nuriko's memories. Once all the seishi are gathered together, they form a baseball team. . . .
