Shoushun is a nyosen (female sage) who resides at Mt. Hou. She is among the fifty oracles dedicated to caring and protecting the young kirin (a creature that chooses the ruler of each kingdom) that are born on the mountain.
Shoushun was from village in En that was suffering from Setsuzan (the destruction and devastation of one's kingdom caused by a corrupt king) caused by the previous king, Kyou-Ou, repressing his people. One day, her village had burned down to the ground and only the village children survived the fire. She came upon the shrine of Oubo and prayed to Seioubo of Gozan to be taken to Mt. Hou and become a sennin. Shoushun held onto a fallen pillar and kept chanting to Seioubo until she was visited by the people of Gozan and became a sennin.
When Shoushun meets Enki, she becomes his frequent companion and tells him of his duty to eventually choose the next king of En, whose presence should stabilize the state of En and bring peace again. However, she is deeply saddened by Enki's cynicism and determination never to choose a king, believing them to be war-mongers who do nothing but destroy lives and entire nations.
(Source: The Twelve Kingdoms wikia)