Dia Hoshina, also known as Amulet Diamond, is a Guardian Character from the anime series Shugo Chara!. She represents Hinamori Amu's desire to shine and be her true self. Unlike the other Guardian Characters, Dia is initially hidden due to Amu’s uncertainty, only emerging when Amu is honest with her feelings. As Amulet Diamond, Amu gains exceptional abilities, reflecting Dia's qualities of brilliance and clarity. Dia plays a crucial role in Amu’s growth and self-discovery throughout the series.