Leontes was born the son of a prostitute and a nobleman of House Capulet . As a boy, he was shown to have grown up in harsh conditions. Leontes' mother died while he was very young. In her dying words, she revealed to Leontes that he was the son of a nobleman of House Capulet and lamented that, in a better life, they may have lived as nobles. Upon hearing this, Leontes swore vengeance on the whole of House Capulet. After her death, Leontes was placed into the care of a member of House Montague, and from then on, he proceeded to poison and murder his way up the ladder of inheritance until he became the head of House Montague.
Later in his life at a ball, Leontes approached a daughter of House Capulet, Volumnia, and a bond of love grew between them. However, Leontes left the woman who would eventually become mother to Tybalt Volumnia De Capulet in favor of marrying Portia Clemenzia de Ebe, and together , they had a son named Romeo Candore De Montague. However, Portia would eventually leave him, after growing hateful of his tyrannical displays of power over the people.
Eventually, at the near end of the anime, it has revealed that he wanted to be loved, however, he made it so that he would receive fear from people instead. When this was revealed, Leontes showed some compassion towards his sons, Romeo and Tybalt. At that very moment Leontes attempted to surrender to Juliet; however, that resulted to his death when Mercutio slew him.
Leontes is most strongly characterized by his strong hate of any mentioning of the House Capulet. He rules the people of Neo Verona with an iron will, executing the use of the Carabinieri to quell any rebellion among the people.