Nightingale Hakui, known in Japanese as ナイチンゲール 白衣, is a character from the mobile game and anime series Monster Strike. Based on the historic figure Florence Nightingale, she is depicted as a guardian angel in a white coat, symbolizing compassion and healing. In the series, Nightingale Hakui plays a supportive role, aiding her allies with her healing abilities and strong sense of justice, often serving as a moral compass and a source of comfort for the team during difficult battles.