Sai Shou/History and Plot

==Anime==
When Shuurei first met Sai Shou, he took her to the man she assumed was the leader. She began to do business with that man and manages to convince him with her spirit. After receiving the Merchant's Guild's support, Sai Shou tells Shuurei that everyone in the Rin Clan had been murdered a few days prior, leaving no survivors. This calls into question the identity of the pink-haired man she had been travelling with. She leaves the Merchant's Guild without finding out Sai's real identity.
He formally introduces himself as the Head while Shuurei is recovering, surprising and impresing her that he was able to become the leader at such a young age. Rou Ensei tells Shuurei that Sa Shou has a twin sister, Sai Rin who is the Provincial Head of the Merchant's Guild in Koren. He promises to devote 80% of the Merchant's Guild's resources to assist the new governors. He will do this in return for the restoration of peace in Sa Province and uprooting the Sa Clan's power and corruption.
He dispatches the Merchant's Guild's mercenaries to bring peace to Koren after the Sa Clan's selection ceremony. Later, Shuurei finds out that Sa Chuushou had ordered Sai Shou to make a new Sa Clan ring, but Sai Shou betrays him, saying that he may be a merchant but he still has morals.
He was also the one who delivered poison Seiran ordered.
After the incident with the Sa Clan, he realized that the blood of a government official was flowing through him after all so he resigned from the Merchant's Guild. He was last seen studying with Ensei to to become a government official.