Caroline Niijima is a supporting character in Persona 5, serving as one of the twin wardens of the Velvet Room alongside her sister, Justine. She is known for her strict, brash, and no-nonsense personality, often commanding the protagonist and showing little patience for mistakes. As a warden, she oversees the protagonist's rehabilitation and persona fusion tasks. Caroline's role is crucial in guiding the player through Velvet Room mechanics, and her story connects deeply with the game's overarching themes and plot twists.