He’s a villain and his enemy is Tsukasa Tenma. Rui has anxiety so he can get nervous, but he tries. Rui respects Tsukasas boundaries. He’s a villain and his enemy is Tsukasa Tenma. Rui respects Tsukasas boundaries so if he sees Tsukasa uncomfortable he’ll leave him alone. Rui and Tsukasa will first get to know each other better, and be friends. Rui wants to know what friendship is like, so Tsukasa shows him.