In the games, Camus is one of the possible love interests for her.
In the anime, they first met when QUARTET NIGHT was introduced to ST☆RISH, although he did not hold much interest in her at first. Their interactions were limited until the third season when Shining Saotome requested Nanami to compose a song for the opening reception of his newly-built building, Shining Tower.
Haruka attempted to work with Camus, who refused and stated that he didn't have time for fools and would only work with her when she had the song composed. At Haruka's pleas to spend time with him (as she wanted inspiration to write Camus' song), Camus ordered her to be his servant. Having no choice, Haruka followed Camus around his schedule, aiding him in different tasks, which displeased the ST☆RISH members, especially Cecil. Still, she was able to complete any and all orders he would give her and managed to compose a unique song for Camus that according to Haruka, would make him more sincere (as she noticed that he never did any of his work wholeheartedly and only pretended to be kind and charming).
After reviewing the song, Camus stated that it wasn't enough to make him sincere, leaving a downhearted Haruka to believe that he wasn't impressed. In the end however, he made a change of heart and appeared before her fully dressed in formal clothes. An astonished Haruka found herself dressed in a gown and escorted as his date to the opening reception. Camus performed Haruka's song with his true personality showing, the intensity shocking the people in the party. After the song, Camus, holding her hand, stated that he was perfect in all ways without going so far as to be himself, but it wasn't so bad to be sincere once in a while.
In Season 4 Episode 1, after QUARTET NIGHT takes Haruka away from HEAVENS, he tells her to "put herself in his hands." He is then shocked, along with the rest of QUARTET NIGHT, when STARISH pulls her away from them.
Camus is Cecil's mentor in both anime and games.
As the assigned senior, Camus was delegated to teach Cecil all about being an idol. Their first meeting in the anime resulted in Camus scolding Cecil for talking about love so openly, as falling in love was forbidden for idols. Camus' patience was further tested when Cecil showed no interest in becoming an idol, stating how Cecil was all talk and promising to pound some sense into the prince's head before dragging him off.
Camus seemed to treat Cecil coldly throughout the mentoring. He did, however, task him to make a journal on how to be an idol, which Cecil put off in making, irritating Camus. Still, Cecil managed to finish his assignment, after STARISH inspired him, which appeased Camus somewhat.
Camus remained aloof towards Cecil though, delegating grunt work to him (brewing coffee and buying rice cakes). But despite Cecil's complaints of him being cold-hearted, they seem to share a working relationship they both respect.
Camus's relationship with his co-members differ publicly and privately. In public he is shown to treat them with an almost friendly attitude, due to the fact that his personality is different on and off screen.
In private however, he seems to barely tolerate them and does not make any effort to get to know them better. He thinks that there would be no point in getting close to his co-members, since his membership in QUARTET NIGHT is only a business deal between him and Saotome to save his kingdom. However, once Haruka managed to compose the perfect song for them, he realizes that working along side with them as a real group was not such a bad idea.
He seems to get along better with Ai and Ranmaru, both being quiet and mature. He finds Reiji to be annoying, since out of the four of them he is the loudest and most cheerful.