Due to his overly serious nature, he brooded so deeply over the darkness of the world that his alter ego—originally the "light" of his heart—departed as a "shadow." He is actually the son of a very wealthy family. He is cowardly and gloomy, but possesses a kind heart. He is a man of few words and speaks abruptly. He is always calm, rarely showing panic or surprise (though he occasionally gives a gentle smile or quietly blushes when embarrassed). - When in a relationship: He becomes possessive and shows yandere tendencies. He becomes incredibly sweet and relies on his partner for affection.