Kou Reishin is in charge of the Civil/Public Administration Department, which makes him Kouyuu's bureaucratic superior as well as adoptive father. He finished second in the Imperial Exams, earning the title of Bougen. He is a good friend of his fellow official Ko Kijin, many of whose strange masks he makes despite being one of the few people who can withstand the sight of Kijin's bare face. Kijin describes him as being crafty and coldhearted, but Reishin usually seems very cheerful, easy-going, and even childish. Kijin and Reishin are also friends with Tei Yuushun, who placed first in the Imperial Exams.
He often engages in devious and secretive behavior, especially regarding his family. He is the only member of the Kou clan who knows that Shouka is The Black Wolf. After Shouka left the main estates nearly fifteen years ago, Reishin became the head of the Kou clan, but most outsiders have been led to believe that the clan leadership belongs to Kou Kurou, their youngest brother. Despite Shouka's public estrangement from their clan, in private Reishin remains very respectful to his older brother, whom he has been trying to protect since learning Seiran's previous identity as the exiled prince Seien.
Reishin is overprotective of Shuurei, although he has gone to great lengths to keep her from learning about their kinship for fear that she might blame him for supplanting her father. He is reluctant to let her marry anyone else, and has even said that he wished he could marry her himself until Shouka pointed out that Reishin is already married. He secretly sponsors Shuurei to take the Official Exams; afterward, he is accused of manipulating the results and is sentenced to house arrest, outraging the Kou clan into a work stoppage that shuts down half of Saiunkoku. The charges are dropped after the arrest of the real criminal, who started the rumors and was involved in illegal activities. At the manga Reishin's hidden past was revealed that there is only him, his brother and his niece in this world.
Reishin also has a wife named Yuri-Hime, the half sister of the former emperor Senka. She does not appear in the story until the 13th novel. Reishin fell in love with her when they were children and was often rude to her, refusing to acknowledge her disguise as a servant boy named "Yuzuriha". Though Yuri had been intended as Shouka's bride, Shouka broke off the engagement supposedly because he expressed no interest in her.
The novels mention that Reishin plays the biwa, the Kou clan's traditional instrument, as his brothers do. In the 13th novel, Reishin is finally exposed to Shuurei as her uncle from her investigations on Kouyuu's behalf; stripped from his position as the Chamberlain of Civil Administration Department, Reishin plans to return to Kou province. [Source: wikia]
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