This is just my two cents but I think the girls should disappear completely. However, I think as Nicole get closer to solving the mystery that she should discover them or what happened to them one by one. That way you could still use the amnesia aspect but it will give Nicole something to work on while also discovering clues. She could spend time with the victims and help them regain their memories which will give her more insight into the crime and the culprit (if when she discovers them that they are still alive). One victim can eventually led to next and then eventually to the culprit with the help of all the clues that Nicole has gather throughout the game. Again, just my two cents. I rather have the game sooner than later and toning down the dark/scary/horror stuff might help you finish it sooner since it might be less work.
I would be nice though if you do another mystery like Nicole to maybe have 3 modes instead of 2: normal otome, mild mystery, and scare your pants off mystery/thriller
. I'm not into that stuff but I would definitely play all modes since you and company do such a great work. I would be scared but I know that I would also be enjoying myself with the artwork, writing, story, music, gameplay, etc.
He didn't send me the final scenes yet, on which I suppose the culprit will talk about his reasons... 