Needs an actual plotline in order to be fully engaging.
That is actually a pretty bad idea for the way the producer of games like this, at least at this stage, any actual plot would equal reaching an end point, whereas this is just sandbox harem building. Honestly the only endpoint I could see making sense is a time limit on the school portion, with afterwards based on fame and maybe money status, your character opening up their own hero agency/ harem home base which all the hero students join, while midnight/mt. lady being sort of scouts for more heroines to be added to your hero agency. But obviously, I don't really know where the maker of this game plans to end this at.