Kai Yu

Kai Yu (櫂 瑜 Kai Yu) is the former Governor of Koku Province and current Governor of Sa Province.

Personality & Characteristics
He is said to be the oldest man to ever hold the position of governor in Saiunkoku, but held such a notorious charm that if he would be thirty years younger, even someone like Shuurei would fall for him.

Plot
He asked the previous Emperor to appoint him as the governors of both Koku and Sa provinces, but was refused because of his old age. Kai was the guardian of Eigetsu when he applied for the ministerial exams, and passed Ka Shin's medical documents on to Shuurei.

When Shuurei and Eigetsu are appointed as the co-governors of Sa province, they ask Kai to succeed them as governor in the event of their deaths. When they are dismissed from those positions, he does succeed them and gives up Koku Province to govern Sa Province and become Eigetsu's mentor.