She told Butterfly that she could not fall in love with him, and would not fall in love with anyone, but that she would care for him. She hasn't made any promise to love any of them. The closest would be her body guard or the musician (if one takes into account the previous soul's memories), but otherwise she's made it clear that she cares about her harem but is not in love with any of them.
Sorry, ignore my last post. I'm just waking up and apparently can't read. LoL
straight up >:)
MC tells them upright she can't be faithful to them alone. A lot of harems have the mc 'say' they'll be faithful but make up absurd reasons and situations that "make" them take on multiple partners. That or they cluelessly make everyone fall in love to make them seem less of a hoe/man hoe. This harem as realistic as it can be for a historical fantasy harem setting.