A mysterious girl with a ray-shriking device shoots at an "innocent" boy who slowly shrinks as an effect of that shrinking device. His younger step-sister is at home, she's surprised to see her big step-brother way shorter than her and gradually shrinking further. She's puzzled but also excited about this situation. The tiny man though has to endure her clumsiness. She can't wait to see him shrink to doll size so she can play with him and recover that time when her stepbrother used to bully her when she was playing with her dolls. The revenge is just a few inches away.
Little Step Sis (now the big one) decided it is the time to play with dolls using her shrunken step brother as a Ken, doesn't matter the age, when they were younger he used to bully her every time she played with them so she never enjoyed those times. Now she can finally enjoy with a little extra. While playing as "Ken", step bro is shrinking even more to the point where even the dolls are giantesses. Step Sis gives him a break and she goes away for a few minutes, step bro takes advantage to do some dirty job to his "dream doll", and you'll also know why he used to bully her step sister for playing with dolls. Step Sis is back but she couldn't find him, he's so tiny that he's almost invisible. Will she find him?
Step Sister "plays" with you until she falls and rests, so you decide to get away from her and get to a "safer" place. But that place is safe until Stepmom comes home. She's totally unaware of you and of the situation you're living in now. She takes off her high heels and starts to do some housework with the hoover putting you in big trouble, she even thinks you're a roach. After cleaning a bit, Step mom decides to rest and get comfortable on the sofa. You tried to get her attention but she can't hear you, you're too tiny. You climb her and try your best to get saved by her, your efforts will just put you in more trouble.
"Tiny Little Step Bro" you're still shrinking and while you lose energy you faint and have a strange dream of being angrily crushed under Step Mom's foot. Waking up on Step Mom's bed you realize how lucky you are for being still alive, even watching Step Mom (totally unaware of you) fingering and enjoying herself, only to be disturbed by Step Sister who can't find you. You're trying your best to get noticed but you're absolutely tiny now, Step Mom and Step Sis are looking for you but with no luck. Finally, you get an opportunity to get attention, you'll get on Step Sis' lollipop, but you're still no luck and get stuck on the wet sugary lolly. Step Sis doesn't notice you and slowly licks and enjoys her lolly with you stuck on it. She puts you in her mouth, you are getting that sweet taste too on Step Sis' tongue until she feels something off. She finally finds you and quickly shows it to Step Mom, who's shocked at how small you have gotten.
Step Sis torments shrunken Step Bro with her ridiculous doll role-playing. She applies makeup on him and dresses him up for the girls' gathering in the doll house. Step Bro's gotta be a maniac since he attempts to kiss and have sex with one of the dolls. Step Sis doesn't like that, so she punishes him by shrinking him smaller and smaller. Step Sis holds the doll in one hand, dangling it over her open mouth till Step Bro loses his grasp and slides into the hatch. It turns out it was just one of his "bad" dreams when he fainted due to the loss of energy while shrinking. He's so small now that Step Mom is troubled. Step Sis, being Step Sis, needs to busy herself using Step Bro while Step mom is out for a few minutes. He's hungry, so she decides to play a game with him in which he must climb her massive foot in order to receive food as a reward. He succeeds unexpectedly, but Step Sis is not content; he has another run to make. He has to go on Step Sis's panties and stay there until she gets him something to eat. Needless to say, he makes it, so she carries him around the room as he's in Step Sis panties fastened in the elastic. She gets him a Banana, a gigantic banana from his perspective, but while Step Sis is absent for a few seconds something "terrible" is about to happen.
This is the final chapter of the series. Tiny Step Step Bro is stuck on the banana that is taken by Step Mom totally unaware he's on it. Before eating it she decides to play with it, as you know, the banana resembles something else, and step mom recently been very horny. She eventually finds out he's on that poor banana, and she gets mad, really mad. She wants to end this situation so she goes out to find the mysterious girl who's shrinking all men in the town and to ask her to turn her step-son to his original size. Meanwhile, Step sister plays further with Step Bro, she tricks him and puts him in a glass of water where he can freely swim, how the hell he didn't know that she's gonna drink that water?! Step Mom is suddenly back, so Step Sis being afraid of making Step Mom mad again spits step bro in the palm of her hand. Step Mom comes back with a tiny man she found on the streets, he claims he knows how to turn people back to their normal size. In exchange for this secret, he has a few requests, wants to see the 2 girls completely naked, and meanwhile wants to be placed in Stepmom's heels, as it seems he loves the smell. Well, Step Mom is not stupid, she knows he's a pervert so she accepts his second request, with a catch, she puts her foot in that shoe and crushes him. Actually, Step Mom received the Shrinking/Growing device from the mysterious girl, there was no need to bring that man in, but she just wanted to use him. Step Bro will finally get back to his normal size, but he has to know that he can get shrunk anytime by Step Mom or Step Sis if he doesn't behave. Extra content at the end.