This game made me cry (in a good way). I have not been able to get any of the good endings yet, but i will keep trying (if anyone has some tips let me know). I am REALLY attached to Dizzy but I do love all of the girls! Amazing game and cute art!
Honestly, what I ended up doing is getting a notebook and pencil, and when the final day comes, I check the stats to see how many times I did each activity with the girl in that cycle. When she dies, her last words are a hint, so next time I get that girl, I adjusted on that. Eventually, I got all 4 good endings this way. Hope this helps.