Maybe I don't understand something, but I just don't see the point in this character (exactly as a character, with a well-developed model, personality, etc.), if this character for the plot in general and for the MC story in particular can be replaced by a simple offscreen character.
And maybe I would see the meaning in such a character if it was a dramatic story about realism, but this is a harem game, and in harem games there is a different principle of character perception. And for me such a character just spoils the integrity of the harem in this game.