In "Shizuko's Daughter", what were Yuki's father and stepmother's names?
Yuki's father's name was Hideki Okuda. Her stepmother's name was Hanae. I don't believe Hanae's maiden name was ever given.
Hanae worked as a secretary at Hideki Okuda's place of employment. She was very pretty, and Hideki began an affair with her while he was still married to Shizuko. Shizuko knew her husband was cheating on her, but did not confront him because she wanted to avoid a custody battle for their child, Yuki. Shizuko knew that, because Yuki was their only child, her father would be granted sole custody of her by the Japanese courts should Shizuko divorce him. Although it most likely was not the only cause behind the depression that led her to kill herself, Hideki's philandering arguably played a great part in creating the conditions leading to Shizuko's suicide. One short year after Shizuko died, Hideki married Hanae, and brought her into their home.
Hanae was a selfish woman who was very concerned with what others thought of her. She was barren, and bitter that Hideki did not allow her to have a child before they were married. Hanae was insanely jealous of Yuki's devotion to her departed mother, and did everything she could to sever the young girl's ties with her mother's family. Hanae considered Yuki's coldness towards her to be evidence of poor raising, and constantly berated Hideki for not being more strict with his daughter.