Hiiro no Koku  

Hitozuma Inran Choukyou: Etsuko no Himitsu, Secret of a Housewife, The Time Colored Scarlet, Time Colored Scarlet, Time of Pink, 비색의 각, 人妻淫乱調教~エツコの秘密~

According to the manga "Sanbun Kyouden," a woman who is a homemaker experiences being assaulted by multiple individuals. To her surprise, she discovers that she enjoys these encounters and her existence transforms into a sequence of increasingly explicit sexual escapades.

On May 28, 2008, Strawberry Jam re-released Hiiro no Koku under the name Hitozuma Inran Choukyou: Etsuko no Himitsu (人妻淫乱調教～エツコの秘密～).(Source: AniDB)