The White Children, also known as the 'Doll Children', are a rare breed of children born in the Hyou Clan. Their birth is actually the side effect of using the Red Immortal's powers. These children are mostly stillborn, however, even if they survive, they don't live long. There were some exceptions though. Hyou Riou (elder) for example.
The White Children possess a magically protected body that can stop the time from birth. As a result, they possess perpetual youth and longevity. But that does not mean that they are immortal. Due to the benefits their bodies possess, they serve as a perfect vessel. Most of them were used up by Hyou Ruka and Hyou Shoukun for this reason. The White Children all possess extreme and flawless beauty so they are often called 'doll-like', hence the name 'Doll Children'.
These children are similar to living corpse. They don't move, eat, sleep or even blink. Unless they are taken care of, they die eventually. However, they are able to become like normal humans if they get extremely motivated, like Riou (elder).
Known White ChildrenEdit
Hyou Riou was born as one of the White Children of the Hyou clan. At first, he managed to survive for a few years because of his sister Ruka's care. She handfed him, sang to him, played the erhu for him and personally cared for him. However, he first started acting on his own as a normal human after meeting the Rose Princess for the first time.
Hyou Shoukun, being the Red Immortal, was forced inside a human body by Riou's father. When the human body expired, the Red Immortal was given a White Child as a new vessel each time the previous vessel expired. In order to save the life of her daughter, Kou Shuurei, Shoukun sacrificed her physical White Child body, and Shuurei became the current vessel of the dormant Red Immortal. Ruka mentioned that most of her 'doll-like' older sisters were used up as Shoukun's vessels.
Hyou Ruka is Riou's elder sister. After becoming the High Priestess, she had to maintain her inhuman powers for decades for the lack of a successor. To keep herself alive, she used up many priestesses and White Children as her vessel. Only few of her vessels were White Children as most were used up by Shoukun. She herself wasn't born as a White Child unlike her younger brother Riou.