As Prince Endymion, Mamoru seems to possess no special abilities or magical powers of any kind; but carries a large sword as a weapon to brutally wound his enemies
He has short black hair and blue eyes. He wears a black suit with silver armour and a black cape. He is equipped with a long bladed sword.
One thousand years ago, Endymion was the prince of a prosperous and mighty kingdom on planet Earth. He had met and fallen madly in love the tender-hearted Princess of the Moon, Serenity. But when the people of Earth were all brainwashed by the evil force of pure dark energy, Queen Metaria. Only strong-willed Endymion managed to maintain his sanity. He demanded his bewitched subjects to stop causing a meaningless war between the people of the Moon, but was stabbed to death by a trusted ally in a desperate attempt to protect his beloved sweetheart, Serenity.
One millennia later, Prince Endymion was reborn and reincarnated into modern-day Tokyo, Japan, as a young man named Chiba Mamoru. His memories of his previous life began to return to him after he lost his present day memories in a car accident that took the lives of his parents. After Mamoru was mortally wounded, the Silver Crystal was revealed within Sailor Moon and both regained their past memories before he was kidnapped by the Dark Kingdom.