Whenever I try reading a harem series (for whatever reason) I never manage to overlook the fact that they all fall for a dude based on what is really extremely basic courtesy anyone should extend to anyone else. Like "he's nice" or "he smiled at me" or "he told me it would be okay when I was stressed out" or probably "he gave me directions once."
And I'm like, what happened to these girls to make their standards so low? Have they only ever been around abusive assholes their entire life before? Do they have untreated PTSD? Is Japan just a society of completely self-absorbed egotists such that just being polite and decent becomes irresistibly rare and attractive?
Anyway, yes, they should all just forget about him and fall for each other instead, that would be less demeaning.