She had an innocent young face. Her appearance with the fine dark lines drawn above her shaved brows and teeth darkened with ink as well as her long black hair nearly touching her feet showed her high birth.
While Masahito was just her half-brother, Midori and Keiko were her sisters. As eldest sister, she had disciplined the other girls firmly, but always with such love and gentleness that they were eager to obey, just to please her. Yukiko and Masahito had been very close for a half-sister and -brother, but shortly before her death a certain coldness between them was noticed by Midori. Also her mod had changed from sunny, tranquil to moody and withdrawn.
Yukiko always recorded her thoughts, as well as her daily activities, in her diary. The diaries were destroyed by Lady Niu after finding Midori reading them.