I was initially planning to give it 4, because as far as cohabitation sims go, this one isn't bad at all. But upon reaching the ending in around an hour or a bit more, it left a bit of an unpleasant aftertaste so bumping it down to 3. Even so it's a good 3, meaning absolute middle of the road but if you are a fan sure, it's a decent one.
Story is as basic as it gets, parent gone for a month, you and sister live together. Sister starts a bit as a tsundere but quickly mellows out, probably too quickly. It's as basic and boring as it gets but it also doesn't meander and does exactly what it needs to.
Gameplay also couldn't be more basic if it tried, do part-time jobs, buy stamina drinks, one time gifts, videos, food, do night crawling and all that. If you tried any single one of those before you know the drill. It is also very easy, you can effortlessly do all the steps for the best ending and 100 stats in half of the time you need, and skipping other 15 days is pretty fast too. Wish there was an option to skip to the end but it's a nitpick if anything.
So my issues lie mostly in story progression events, although writing itself is not inspired as well. While night portions are animated and nice, progression stuff like blowjob, sumata, missionary and doggy are still CGs, even as you repeat them with "slow-rough" like there should be an animation, but there isn't. If it was the only thing i wouldn't care, but eventually you will do all that stuff outside during dates and instead of unique CGs they just repeat the same ones. But what killed me and forced me to give it 3 is the very ending, what i worked towards and my reward was... the same series of CGs. Bugger off. It's such a weird thing to cut corners on and leaves a bad taste after an overall positive experience, like finding a dead fly at the last bite of the otherwise tasty cake.
Storywise game definitely could do more as well, voice acting is very much fine but writing is SO minimalistic and barebones it barely gives you anything to care as well.
Overall yeah, you probably noticed i repeated the word "basic" a lot, but this is a perfect epithet to describe this whole experience. If you are a fan of cohabitation sims it's like a fastfood variant, it's fine and it works and worth spending an hour or two on, but you very likely will forget about it in a week.