Based on a voice drama.

You warned your brother, Kiyora, about how dangerous it could be to mix his sleeping medicine with alcohol.
You wake up suddenly in the middle of the night to find him kissing you...?

It seems as though the sleeping medicine was far too effective. He's practically asleep.
He starts whispering to you in a low, rough voice, and rubbing you all over...
You know you have to stop him, but you don't have the strength...

Your parents are sleeping downstairs. All you can do is try not to wake them...
Your heart beats faster as your body gets more and more sensitive, and if he keeps making you cum like this, then...

The next day, Kiyora acts like nothing happened.
Does he really not remember what happened at all...?

(Source: DLsite garumani)