For 10 points, name this author of Masks.
One of this author's characters covers up an illegitimate child fathered by her grandson Kazuya; that woman also prevents a nascent incestuous relationship between her grandchildren Takao and Ruriko. Another character created by this author hires a private investigator after her daughter discovers red lipstick on her father's ribs. In one work by this author, Yukitomo takes his daughter-in-law Miya as a lover and that work opens with his wife Tomo looking for a concubine for him. In another novel by this author  one character wrote an essay for a lover about the Rokujo Lady after that lover, the father of her twin children, goes to serve in the Sino-Japanese War. Harume becomes pregnant after Ibuki unwittingly sleeps with her during his liaisons with the widowed Yusako, who believes the entire affair was orchestrated by Mieko to continue her lover's family line after the death of Akio in that novel by this author of The Waiting Years. For 10 points, name this author of Masks. 
One of this author's characters covers up an illegitimate child fathered by her grandson Kazuya; that woman also prevents a nascent incestuous relationship between her grandchildren Takao and Ruriko.
Enchi Fumiko [prompt on "Fumiko"]