Like her name, she is the thirteenth daughter or princess of the Ran clan. She is the half-sister of Shuuei, Ryuuren, and the Ran triplets, but she has the closest relationship with Shuuei. She was sent to the palace to become Ryuuki's consort by the triplets (with the choice to either become a consort or marry Seiran), and she soon became a target of assassination by a mysterious group. The head assassin was none other tha Jin Shiba, her first love, who was a death-row prisoner. After Shusui's departure, Jyuusan-hime replaced her position as head lady-in-waiting and later on challenged Shuurei in a contest of making steamed buns. She has all the skills of both being a princess and a fighter, being raised by the Shiba family, a famous retainer clan of the Ran clan who specialized in combat. By looks, she resembles Shūrei so much that Shūrei was once given the task to impersonate her. She is the most likely candidate to be Ryuuki's concubine, should Shuurei continue to show disinterest in the time period that was given