SpoilerCamille was Claude's childhood friend, and it is suggested that both might have had feelings for each other in their childhood. Claude brought her stray cats and played with her in her garden since she was not allowed to play outside. After confessing her love to Claude, she wanted to make a promise with him, which was make him promise her that he would never stop visiting her even if someday she was married, but Claude got upset.
In chapter 6 she shows some jealousy towards Yune due to her closeness to Claude. At the end of the chapter, it is indirectly hinted by Yune to Claude that Camille might still have feelings for him.
CV: Yahagi Sayuri