This is a game where you do night crawling without waking up your sister in law. Lick, rub, pluck and insert and finger-bang. ...use a variety a way of touching to conquer your sister-in-law.
The leading character is a virgin, reserved, "otaku". His work is home security.
By strange accident, his father remarried and he got a new family.
...My sister-in-law looks at me really coldly.
However, I am panting and suffering with mental anguish over the sister-in-law in my new family.
I couldn't stand it anymore so I decided to do night-crawling on __/__/20__.
If I am found out she will look at me even more harshly, and treat me as sheer waste.
Source: The Game Website.