Character Profile

This is a story of a mother and a sister being stolen away and seduced by a stranger man.
One day, a stranger man suddenly intrudes into the protagonist's home. At first, everything seems perfectly normal. But as time ticks away, the bond between the protagonist's mother, his sister, and this man begins to grow tighter and tighter, while they drift further apart from the protagonist himself.
On the very night this man stays over, strange and forbidden moans begin to echo from the guest bedroom—and it sounds just like Mom...