Dr. White S01 8

A mysterious unidentified woman in white coat was found collapsed in a park early in the morning. The woman, who calls herself "Byakuya" (white night), lost her memory and has no general knowledge about the society. However, the woman has an amazing medical knowledge and is able to correct misdiagnosis by doctors. The woman is not a doctor but is able to diagnose the right illness based on little information. What is the identity of this woman?