Sourin (宗麟) is the kirin and Saiho of the kingdom of Sou, which has prospered for six hundred years under the rule of Senshin. Out of affection for her, she is nicknamed "Shou-Shou" (昭彰) by the members of Senshin's family.
When Sourin found Senshin, he was a prosperous innkeeper[1] in a small harbour town in Kou Province of the Kingdom of Sou. Well-regarded in the community, he was known for frequently consulting with members of his family and respecting their opinions, which he attributed to the success of his business. After being chosen as king, Senshin continued the practice and included Sourin in his consultations[2].
Like all kirin, Sourin is naturally benevolent; Senshin's family describes Sourin as being capable of caring even for the most terrible villain in the world. Regardless, she shows relief that Rikou has returned safely from his latest outing in the world and she is very much regarded as a member of Senshin's family. She has the appearance of a young girl and, characteristic of kirin, she has gold hair. Little else is known about Sourin, though Shoryu mentions to Enki in the last chapter of The Twelve Kingdoms: The Vast Spread of the Seas that she is rumoured to be very refined.
In episode 21 of the anime, Enki notes that it was Sourin who first located him in Hourai.