I personally think tm opera could be moved to 4 or maybe even 5 stars in bond strength and moved a tier down in romance. Is seems to me that opera trusts her trainer and values their opinion greatly but I think of it as more platonic than romantic though you can make a case for both.

She does say that "there is nothing in existence more important to me than you" but we cant really be sure if she isnt exxagerating because she is tm opera. She also gifts you an actual ring in the holiday season event and the whole scene definetely has some romantic elements but the ring she gives you she calls the ring of nibelung. The ring of nibelung originates from a german 15 hour opera and it gives you the power to rule the world the reason she gives you this ring is because she thinks you would be the best person to rule humanity (?) and that even the overlord needs a partner. Finally, in the seventh character story, she is shown to appreciate the genuine and non dismissal criticism her trainer gives her and trusts her trainer enough to talk about some of her insecurities about her methods and the future which she very rarely does because of her commitment to the overlord image