Father's woman

Before I could remember, my mother was gone, and I live with my father. One day, a flashy woman came to our house. Apparently he was my father's girlfriend...and then he began living a strange life with Kaho. While my father was away, I was alone with Kaho. Perhaps because he treats me like a child... I couldn't take my eyes off the defenseless Kaho walking around in just a bath towel. And even though she was my father's boyfriend, Kaho's presence grew more and more day by day.