I really liked the writing and the cast. The only 2 suggestions i have are to speed up the fade-in/fade-out transitions; and remove or at least lower the affinity requirements (unless you have a reason you need them), specially for Yokubo and Yui, since you can only "level" them in the weekends. I don't think a "i should raise this number" feeling is good for the immersion. And i'm not sure what the plans are for the weekdays, but for now, after the first 2 weeks you just have to skip them, since there's nothing to do.
Other than that, very happy with it. I'm not really into games with "depression" as plot, but the way it was written was quite enjoyable. Well done.