Kazuki is Miki's 13 year old brother. Kazuki lives with his father. He is seen in the opening and is properly introduced in episode 2. He poses as Miki's boyfriend so that other boys will not flirt with her. He is somewhat sickly and is afraid it will prevent him from doing things he wants to do but Miki encourages him. His dream is eventually to become a doctor. (Source: Pretty Cure Wiki)