Yuki Endo 「??? ???」 was one of the orphans from the Hyakuya Orphanage. She is mentioned in Guren Ichinose: Catastrophe at Sixteen.
Unknown.
At some point in her life, they were picked up by the Brotherhood of a Thousand Nights, a religious organization infamous for cruel experimentation on orphans.
The orphans move out shortly before the vampires destroy the Hyakuya Sect.