"Um, it's not normal to use your sister as a masturbator."
My younger sister Ayuno is gloomy and taciturn. I treat her like a masturbator and use her for sexual relief every day, but recently the room has been smelling strange. When I looked for the cause, I found out that Ayuno hadn't taken a bath in a week!
I have no choice, I'll give her a bath.
I'm going to wash my sister's masturbator! A hardcore, rich-smelling sex session begins in the bathroom♪