Quick review, because despite its content the game doesnt really have that much going for it.
Storyline is kinda fucked. You play as a hopeless loser onii-chan with one of the brattiest, most mindfucked little STEP-sister (as though the game couldnt make this any clearer) who practically abuses her bro on a daily basis but is secretly in love with him. Obviously. If this isnt enough imoutos for you, the game also contrives several non-related sisters for you to fuck around with, or rather the other way around, but these are not central to the premise and can be easily ignored.
Gameplay is fairly standard. You work to get cash, and spend all the other times not working raising affection levels and managing stamina. A word of advice is to immediately start working on increasing your max stam because everything, including the H, rely on it.
There are annoying minigames to suffer through, but I got by without really much trouble. As long as you have been working on that max stam its fairly inoffensive, but I cannot for the life of me understand why these need to exist.
As for H gameplay, there are VN sections where you just spacebar until she cums, and there are more interactive scenes where youre invited to mouseclick until she cums. I find the interactive scenes unimpressive as lil sis barely puts out any emotions in any of them. At least the VN scenes are fine, as long as the storyline doenst piss you off. There is VA and slight animations on what seem like live2d.
Just a short comment on the artwork design because I find the idea of a alleged schoolgirl wearing a belt for a skirt as amusing as it is idiotic. Shes apparently not wearing a bra because the straps wouldve needed to be 2 feet long given the continental size of her puppies.
In CONCLUSION...
What can I say? Its just another siscon cohabitation game that clearly took liberties with imouto monochrome, all the way down to the sleep fuck mechanic, but much like a student vigorously copying his friends' homework before school starts 5 minutes later, the work looks impressive but look at its sides will reveal it to be nothing more than a hollow cardboard cut out. To put simply, the game has zero emotional value because its too busy staring at lil sis' massive watermelon jugs. Lil sis wavers so much between love and abuse that theres no consistency to her behavior, and the sex when offered kinda just happen, like a flip of a switch.
Life with a flirty step-sis has practically the same premise, practically the same bratty sis (more tease than abusive) personality, is more barebones by comparison, but because they executed the emotional value better it stands as the superior game.
So can I recommend this? Well, only if you really need a sis that will dress you down at every opportunity, in which case this game is perfectly designed for you. Otherwise, theres simply better siscon cohabitation games available.