Sixth Concubine/History and Plot

==Anime==
===Episode 3===
Though only mentioned briefly in the anime, Shi Ryuuki said that the Sixth Concubine was the person who physically abused him when he was a child. She showed him no love but he couldn't hate her and instead, loved her unconditionally.
==Light Novels==
===Gaiden 4===
Her personality and history in the novels is explored further and in more detail. Being the Emperor's last concubine, she was given the least attention by the Emperor and was jealous of Suzuran. She became so bitter that anything Ryuuki did would annoy her. She would scratch and throw things at him and if he didn't show any reaction, she would become even more violent.
When Seien sees her abuse for the first time (in the novel, at least), he stops her just in time by twisting her arm back. When Ryuuki's mother is about to reprimand him, he gives her a look that sends a chill down her spine. She closes her mouth and Seien makes a few snide remarks about her status and beauty before leaving the room with Ryuuki. Seien thinks to himself that even though she was a famous courtesan, she is a fool for believing that she could seduce the Emperor and for entering the Imperial Harem even though she wanted attention from men.
She throws Ryuuki's favourite bean bags into the pond during one of her tantrums.
Though not explicitly stated how she died, Ryuuki's mother had apparently suffered a horrific death. It was later revealed that the cause of her death was Suzuran, who drove her to suicide by mentally abusing her. One of the things she did was send her poisoned makeup, which disfigured the Sixth Concubine's face. Believing she had lost the only thing that made Senka pay attention to her and bring her into the Imperial Harem, she committed suicide by throwing herself into the Tousen Pond during winter. Her body was discovered by Ryuuki.