Shiro/History and Plot

==Light Novels==
===Volume 4===
While Kou Shuurei is Governor in Sa Province, Shiro and Kuro would occasionally show up in front of her but never doing it in their true forms.
===Volume 8===
Shiro and Kuro follow Shuurei back to Kiyou after the resolution of the Jasenkyou incident in Sa Province.
===Volume 11===
Shiro and Kuro fall into the possession of Shou Yousen for a reason not explained. They are not very fond of him and do not listen to a thing he said but for some reason, they take a liking to Sou Shungai. He takes a liking to them too so he asks Shou Yousen if he could keep them. Shou Yousen reluctantly agrees. Sou Shungai dubs them “Shiro" and “Kuro”.
While Shuurei and Shin Suou are inspecting the prisons, which is a task given to new Censorate officials, she meets a prisoner condemned to death named Shun. As they are leaving the prison, they are chased by assassins, and Shuurei scrapes her wrists while trying to escape. Shuurei realises after a while that she hasn't stopped bleeding. When she returns to the Censorate, Kuro and Shiro do something mysterious to heal her wrists.
===Volume 12===
Kuro enters Shuurei's body in Ran Province while Hyou Shusui is playing the erhu and Ryuuren is playing his flute which allows her to resist the negative effects the instruments would have had on her. It is becoming more apparent that Kuro and Shiro have abilities beyond those of normal human beings.
===Volume 14===
It is revealed that Shiro and Kuro are the Red Immortal’s attendants. Shou Taishi contemplates the Red Immortal's motives for asking Kuro and Shiro to extend Shuurei's life even though she will still eventually die.
===Volume 15===
Ensue admits that he is able to see spirits, including Shiro and Kuro, because he had been living with Nan and Ginjirou for a long time.