I feel like shit. I'm not going to comment for a further time. Sorry.
Take your time and remove yourself a bit from it all and come back a bit fresher.
I know you intended fun things, that there are reasons for the Sofia bullying, that Mc had to be set back for the mentor system and so on and more of those things or can make a guess what you might have wanted. This is not the first story we have read or game played. What you did not take into account though is how setting MC so far back makes him an object of pity instead of sympathy and relatable with confidence based on nothing more he is one of millions of people who can do a karate kick and that confidence makes no sense with his background further..
Who has basically been emotionally neglected for years with serious problem and not a fun problem or one you can easily overlook as a player and what impact that would have on the women around him especially the Mom and Elena besides just Sofia, having everyone have so many bad traits basically every character has to be turned around and feels more like an antagonist as a possible Li would have. (Where if a mentor would really want to give MC a chance to grow he would have to face up to fact that he was neglected by them and left to fend on his own and overcome those emotions, not just the effects of the bullying and false accusation) Maybe have the three mentors have different people introducing them and all be active and working with MC at same time for different qualities/facets as a path per mentor. (One physical/ one learning/one mental for example).
Tone it down, make it simpler and less drama everywhere (especially everywhere negative drama instead of positive drama), let them show more love (not just in hugs or smile or word, but really make it feel he and his life are important to them in actions instead of showing neglect) and have actions now and in past fit if they are meant as a LI that they also cared, or just did not know him at all so are blameless for not acting.
Players also need to breathe and smile especially in a harem, make it so MC has issues from a one time shocking thing for example like a fatal accident of a friend he may feel guilty about he did not stop it, but cannot really be blamed for that the women did try to help with even if means reworking Sofia line (which she needs anyway, who in his right mind would want to ever be in a relation with someone that accused you of a false rape and seriously bullied you for years, even if could forgive you would not forget) and possibly less serious and maybe even have mentor there at behest of the girls for those issues they could not deal with for him since they are not psychologists, Elena as his teacher could be great catalyst for that, but not if her neglect over years is part of the reason he has those problems in the first place and she would be a bit late with him having graduated by now.
Also MC caring for the women firstly and shown might work better as making his first goal in life just being a male trophy wife which would work better as a plot if he was at least kinda loveable instead of a mess and would need for him to be somewhat different from a few years ago as an adult now to make sense they go for him now and not then since we are talking a twenty year old MC and not a 15 yo, even if has been set up as a shota and that should be part of his appeal, well it was not enough a year ago or two years ago when he was also available.

let alone that with his experience as MC he would be able to make someone like Bianca an addict to his dick before she taught him lots unless you are going to add a demon that makes it magical.
You know it is indeed about those details and how it makes a player read a character, just throwing loads of drama in (the drama also needs to make sense and not be destroying the char of the people in game as an LI if they are intended as one, so no unforgiveable sins) and putting MC at rock bottom, does not make for fun and takes incredible skill to keep balance right and not destroy your main girls. Even someone like Drifty (who is a pretty good writer) in Leap of Faith had to go back to start of game to change things in Steph's background to be able to save one of his main girls after he set her up too dark in the eyes of his players and he did not succeed for everyone even after. What characters do or not do in a game matters and sometimes even more as why they did it, last is not always enough if the actions or lack thereof are bad enough in the first place to turn them around.