The Second Princess initially believed her father's lies about Naofumi and hated him, she attempted to make him apologize for dishonoring her father but was treated by him as an annoyance in return. After the Three Heroes Church tries to kill her, Naofumi becomes the only person Melty can actually rely on to save her life as the other heroes, her sister, and her knights are all either being used by the Church or are willing participants in the conspiracy. Because of this, she has become something of a Tsundere towards him, and it's implied that her feelings for him extend beyond what she wants him to hear about. She dislikes being treated by him as a child or being called "second-princess" by him, and gets him to call her by name instead. He's not above playing pranks on her and still uses her for his own convenience; to which he once called her Firo's fiance and spread that to Motoyasu to get him off his case. The end result of this was that when she found out she destroyed his house, with him still in it. She appears to be one of the few people he trusts well enough to keep Atlas out of his bed, a task which would require her to sleep in the same bed with him, when asked, she blushed and ran away. They're fully capable of behaving professionally with each other at times and bickering the very next minute.