Ah... so it's not just the "Ability people think is worthless is secretly OP" but the "girl that would too easily get with the MC otherwise and not allow a harem unless if conflict occurs" trope...
Where the harem is avoidable, but the girls feelings can't be known else it'd stop the harem...
So she's not actually bad... so the conflict is just to make him seem more pitiful... and maybe make an excuse so that he can build a harem or something (cause if she was straight forward in her love with him, he'd be a cheater if he got other girls)....
That's just sad.... like... a conflict created solely so that the MC can get a harem instead of having a single relationship....
Just wow...