Make little sister into oniisan's exclusive sex toy by molesting her in her sleep.

There are three stages of touching in sleep mode.
Finger her loli virgin p*ssy till she's ready, then penetrate her with a grownup-size c*ck!
Show her unwitting boyfriend video of what you do at night!
Relish his heartbreak! F*ck his girlfriend while he watches!
You incestuous cuckolder! Yeah! That's how you seduce a conceited litle sister.

[From DLsite English]