Senshin (先新) is the current ruler of Sou. He is the husband of Meiki and father of Bunki, Rikou, and Ritatsu. The King of Sou has been reigning for 600 years and is known of for the longest reign of the current rulers of Twelve Kingdoms. Should he rule for another two hundred years, he will have the longest reign in the history of the Twelve Kingdoms.
Before becoming king, Senshin was an innkeeper in a small harbour town in Kou Province of the Kingdom of Sou, where Sourin found him. Known as a generous and clear-headed man not prone to impulsive action, Senshin was widely respected in his community. Possessing an open mind, he frequently consulted with his wife and children and respected their opinions; he has attributed the success of his inn as the result of his family's work and had worked hard to keep them involved in managing the business.
As king of Sou, Senshin has continued these practices, with the addition of Sourin to family's consultations. As a result, Senshin's success as king is in part attributed to his ability to delegate and entrust his family members with the same authority that he acts with as king.