Countess Diana Precious is a minor character in Promix Club, acting as Headmistress of Diana Colledge and Tressa's Countess. She also has a adoptive daughter, Ellie as well as Amelina's trustworthy aunt.
It is revealed that Diana is a dedicated and serve headmistress being fully in charge of managing all students, even able to solve the toughest issues. She is amitted to be a strict teacher. Same as her niece, Amelina, she has a fearless personality along with extraordinary intuition of technology.
Nothing much is known about Diana's family before her older sister's royal marriage and coronation to be Queen.