There is very little story here. The game is a "scenario" rather than a narrative experience. It drops you directly into the bedroom with no context or buildup. The characterization of the "Little Sis" is purely archetypal; she exists solely as the object of the puzzle mechanics. Players looking for a story or character development will not find it here.
The "v1 Free" designation usually implies this is either a demo, an early access build, or a freeware release meant to serve as a proof-of-concept or a teaser for a larger, paid version. night attack on little sis sleeptime fun v1 free