Rui Kamishiro is the responsible bodyguard of his friend and idol Tsukasa. Rui, along with Tsukasa, used to be in the musical troupe Wonderland x Showtime. But when Tenma fulfilled his dream of becoming a star, the troupe went their separate ways. But Kamishiro decided to continue helping Tsukasa and became his bodyguard, who does his job well. He protects Tsukasa from creepy or obsessive fans. Protects when they are in public places and can protect themselves from potential danger.